dt-bindings: Clean-up regulator '-supply' schemas

Regulator '*-supply' properties are always a single phandle, so
'maxItems: 1' or a $ref is not necessary. All that's needed is either
'true' or an optional 'description'. Following this clean-up, the
meta-schema will enforce this pattern.

There's one case in tree with 'innolux,n156bge-l21' having 2 phandles.
This appears to be a mistake or abuse of simple-panel as it's 2 different
voltage rails connected to 'power-supply'.

Cc: Neil Armstrong <narmstrong@baylibre.com>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: linux-iio@vger.kernel.org
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> # for iio
Signed-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/display/amlogic,meson-dw-hdmi.yaml

@@ -79,8 +79,6 @@ properties:
 
   hdmi-supply:
     description: phandle to an external 5V regulator to power the HDMI logic
-    allOf:
-      - $ref: /schemas/types.yaml#/definitions/phandle
 
   port@0:
     type: object

Documentation/devicetree/bindings/gpu/arm,mali-bifrost.yaml

@@ -37,8 +37,7 @@ properties:
   clocks:
     maxItems: 1
 
-  mali-supply:
-    maxItems: 1
+  mali-supply: true
 
   operating-points-v2: true
 

Documentation/devicetree/bindings/gpu/arm,mali-midgard.yaml

@@ -69,8 +69,7 @@ properties:
       - const: core
       - const: bus
 
-  mali-supply:
-    maxItems: 1
+  mali-supply: true
 
   resets:
     minItems: 1

Documentation/devicetree/bindings/gpu/arm,mali-utgard.yaml

@@ -97,8 +97,7 @@ properties:
 
   memory-region: true
 
-  mali-supply:
-    maxItems: 1
+  mali-supply: true
 
   power-domains:
     maxItems: 1

Documentation/devicetree/bindings/iio/adc/adi,ad7124.yaml

@@ -45,15 +45,12 @@ properties:
 
   refin1-supply:
     description: refin1 supply can be used as reference for conversion.
-    maxItems: 1
 
   refin2-supply:
     description: refin2 supply can be used as reference for conversion.
-    maxItems: 1
 
   avdd-supply:
     description: avdd supply can be used as reference for conversion.
-    maxItems: 1
 
 required:
   - compatible

Documentation/devicetree/bindings/iio/adc/adi,ad7606.yaml

@@ -31,10 +31,7 @@ properties:
 
   spi-cpha: true
 
-  avcc-supply:
-    description:
-      Phandle to the Avcc power supply
-    maxItems: 1
+  avcc-supply: true
 
   interrupts:
     maxItems: 1

Documentation/devicetree/bindings/iio/adc/adi,ad7780.yaml

@@ -39,7 +39,6 @@ properties:
   avdd-supply:
     description:
       The regulator supply for the ADC reference voltage.
-    maxItems: 1
 
   powerdown-gpios:
     description:

Documentation/devicetree/bindings/iio/adc/avia-hx711.yaml

@@ -41,7 +41,6 @@ properties:
   avdd-supply:
     description:
       Definition of the regulator used as analog supply
-    maxItems: 1
 
   clock-frequency:
     minimum: 20000

Documentation/devicetree/bindings/iio/adc/samsung,exynos-adc.yaml

@@ -46,9 +46,7 @@ properties:
   "#io-channel-cells":
     const: 1
 
-  vdd-supply:
-    description: VDD input supply
-    maxItems: 1
+  vdd-supply: true
 
   samsung,syscon-phandle:
     $ref: '/schemas/types.yaml#/definitions/phandle'

Documentation/devicetree/bindings/iio/chemical/plantower,pms7003.yaml

@@ -25,7 +25,6 @@ properties:
 
   vcc-supply:
     description: regulator that provides power to the sensor
-    maxItems: 1
 
   plantower,set-gpios:
     description: GPIO connected to the SET line

Documentation/devicetree/bindings/iio/pressure/bmp085.yaml

@@ -28,12 +28,10 @@ properties:
   vddd-supply:
     description:
       digital voltage regulator (see regulator/regulator.txt)
-    maxItems: 1
 
   vdda-supply:
     description:
       analog voltage regulator (see regulator/regulator.txt)
-    maxItems: 1
 
   reset-gpios:
     description:

Documentation/devicetree/bindings/phy/amlogic,meson-g12a-usb2-phy.yaml

@@ -36,7 +36,6 @@ properties:
     const: 0
 
   phy-supply:
-     maxItems: 1
      description:
        Phandle to a regulator that provides power to the PHY. This
        regulator will be managed during the PHY power on/off sequence.

Documentation/devicetree/bindings/regulator/fixed-regulator.yaml

@@ -64,7 +64,6 @@ properties:
 
   vin-supply:
     description: Input supply phandle.
-    $ref: /schemas/types.yaml#/definitions/phandle
 
 required:
   - compatible