RISC-V: add Milkv Mars board devicetree

The Milkv Mars is a development board based on the Starfive JH7110 SoC.
The board features:

- JH7110 SoC
- 1/2/4/8 GiB LPDDR4 DRAM
- AXP15060 PMIC
- 40 pin GPIO header
- 3x USB 3.0 host port
- 1x USB 2.0 host port
- 1x M.2 E-Key
- 1x eMMC slot
- 1x MicroSD slot
- 1x QSPI Flash
- 1x 1Gbps Ethernet port
- 1x HDMI port
- 1x 2-lane DSI and 1x 4-lane DSI
- 1x 2-lane CSI

I fixed up some nits Emil pointed out. This merges fixes into for-next
to avoid messing around with some nodes that were removed as fixes this
cycle.

Signed-off-by: Conor Dooley <conor.dooley@microchip.com>

Author: ConchuOD

Documentation/devicetree/bindings/riscv/starfive.yaml

@@ -26,6 +26,7 @@ properties:
 
       - items:
           - enum:
+              - milkv,mars
               - starfive,visionfive-2-v1.2a
               - starfive,visionfive-2-v1.3b
           - const: starfive,jh7110

arch/riscv/boot/dts/starfive/Makefile

@@ -8,5 +8,6 @@ DTC_FLAGS_jh7110-starfive-visionfive-2-v1.3b := -@
 dtb-$(CONFIG_ARCH_STARFIVE) += jh7100-beaglev-starlight.dtb
 dtb-$(CONFIG_ARCH_STARFIVE) += jh7100-starfive-visionfive-v1.dtb
 
+dtb-$(CONFIG_ARCH_STARFIVE) += jh7110-milkv-mars.dtb
 dtb-$(CONFIG_ARCH_STARFIVE) += jh7110-starfive-visionfive-2-v1.2a.dtb
 dtb-$(CONFIG_ARCH_STARFIVE) += jh7110-starfive-visionfive-2-v1.3b.dtb

arch/riscv/boot/dts/starfive/jh7100.dtsi

@@ -13,7 +13,7 @@
 	#address-cells = <2>;
 	#size-cells = <2>;
 
-	cpus {
+	cpus: cpus {
 		#address-cells = <1>;
 		#size-cells = <0>;