imx8m: imx8mn-beacon: Migrate README to rst

Since U-Boot builds HTML documentation, migrate the contents
of the README file to an rst file which can generate the
proper outputs.

Signed-off-by: Adam Ford <aford173@gmail.com>

board/beacon/imx8mn/README

@@ -1,38 +0,0 @@
-U-Boot for the Beacon EmbeddedWorks i.MX8M Nano Devkit
-
-Quick Start
-===========
-- Build the ARM Trusted firmware binary
-- Get ddr firmware
-- Build U-Boot
-- Boot
-
-Get and Build the ARM Trusted firmware
-======================================
-Note: $(srctree) is U-Boot source directory
-
-$ git clone https://github.com/nxp-imx/imx-atf
-$ git lf-5.10.72-2.2.0
-$ make PLAT=imx8mn bl31 CROSS_COMPILE=aarch64-linux-gnu-
-$ cp build/imx8mn/release/bl31.bin $(srctree)
-
-Get the DDR firmware
-====================
-$ wget https://www.nxp.com/lgfiles/NMG/MAD/YOCTO/firmware-imx-8.9.bin
-$ chmod +x firmware-imx-8.9.bin
-$ ./firmware-imx-8.9
-$ cp firmware-imx-8.9/firmware/ddr/synopsys/lpddr4*.bin $(srctree)
-
-Build U-Boot
-============
-$ make imx8mn_beacon_defconfig
-$ make CROSS_COMPILE=aarch64-linux-gnu-
-
-Burn U-Boot to microSD Card
-===========================
-$ sudo dd if=flash.bin of=/dev/sd[x] bs=1024 seek=32
-
-Boot
-====
-Set baseboard DIP switch:
-S17: 1100XXXX

doc/board/beacon/beacon-imx8mn.rst

@@ -0,0 +1,53 @@
+.. SPDX-License-Identifier: GPL-2.0+
+
+U-Boot for the Beacon EmbeddedWorks i.MX8M Nano Devkit
+======================================================
+
+Quick Start
+-----------
+
+- Build the ARM Trusted firmware binary
+- Get DDR firmware
+- Build U-Boot
+- Burn U-Boot to microSD Card
+- Boot
+
+Get and Build the ARM Trusted firmware
+--------------------------------------
+
+.. code-block:: bash
+
+    $ git clone https://github.com/nxp-imx/imx-atf.git -b v2.6
+    $ make PLAT=imx8mn bl31 CROSS_COMPILE=aarch64-linux-gnu-
+    $ cp build/imx8mn/release/bl31.bin ../
+
+Get the DDR firmware
+--------------------
+
+.. code-block:: bash
+
+    $ wget https://www.nxp.com/lgfiles/NMG/MAD/YOCTO/firmware-imx-8.15.bin
+    $ chmod +x firmware-imx-8.15.bin
+    $ ./firmware-imx-8.15
+    $ cp firmware-imx-8.15/firmware/ddr/synopsys/lpddr4*.bin .
+
+Build U-Boot
+------------
+
+.. code-block:: bash
+
+    $ make imx8mn_beacon_defconfig
+    $ make CROSS_COMPILE=aarch64-linux-gnu-
+
+Burn U-Boot to microSD Card
+---------------------------
+
+.. code-block:: bash
+
+    $ sudo dd if=flash.bin of=/dev/sd[x] bs=1024 seek=32
+
+Boot
+----
+
+Set baseboard DIP switches for micoSD Card:
+S17 (1:8): 1100xxxx

doc/board/beacon/index.rst

@@ -8,3 +8,4 @@ Beacon
 
    beacon-imx8mp
    beacon-imx8mm
+   beacon-imx8mn