ASoC: fsi: Add missing properties to DT bindings

make dtbs_check:

    arch/arm/boot/dts/r8a7740-armadillo800eva.dt.yaml: sound@fe1f0000: '#sound-dai-cells', 'clocks', 'power-domains' do not match any of the regexes: 'pinctrl-[0-9]+'

Fix this by documenting the missing properties.
Update the example to match reality.
While at it, improve the document title, and comment the various
compatible values with the corresponding SoC names.

Fixes: 2f52475bac ("ASoC: fsi: switch to yaml base Documentation")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/sound/renesas,fsi.yaml

@@ -4,7 +4,7 @@
 $id: http://devicetree.org/schemas/sound/renesas,fsi.yaml#
 $schema: http://devicetree.org/meta-schemas/core.yaml#
 
-title: Renesas FSI Sound Driver Device Tree Bindings
+title: Renesas FIFO-buffered Serial Interface (FSI)
 
 maintainers:
   - Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
@@ -18,8 +18,8 @@ properties:
       # for FSI2 SoC
       - items:
           - enum:
-              - renesas,fsi2-sh73a0
-              - renesas,fsi2-r8a7740
+              - renesas,fsi2-sh73a0  # SH-Mobile AG5
+              - renesas,fsi2-r8a7740 # R-Mobile A1
           - enum:
               - renesas,sh_fsi2
       # for Generic
@@ -34,6 +34,15 @@ properties:
   interrupts:
     maxItems: 1
 
+  clocks:
+    maxItems: 1
+
+  power-domains:
+    maxItems: 1
+
+  '#sound-dai-cells':
+    const: 1
+
   fsia,spdif-connection:
     $ref: /schemas/types.yaml#/definitions/flag
     description: FSI is connected by S/PDIF
@@ -62,16 +71,24 @@ required:
   - compatible
   - reg
   - interrupts
+  - clocks
+  - power-domains
+  - '#sound-dai-cells'
 
 additionalProperties: false
 
 examples:
   - |
-    sh_fsi2: sound@ec230000 {
+    #include <dt-bindings/clock/r8a7740-clock.h>
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    sh_fsi2: sound@fe1f0000 {
             compatible = "renesas,fsi2-r8a7740", "renesas,sh_fsi2";
-            reg = <0xec230000 0x400>;
-            interrupts = <0 146 0x4>;
+            reg = <0xfe1f0000 0x400>;
+            interrupts = <GIC_SPI 9 0x4>;
+            clocks = <&mstp3_clks R8A7740_CLK_FSI>;
+            power-domains = <&pd_a4mp>;
 
+            #sound-dai-cells = <1>;
             fsia,spdif-connection;
             fsia,stream-mode-support;
             fsia,use-internal-clock;