riscv: dts: starfive: add Milkv Mars board device tree

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

Add the devicetree file describing the currently supported features,
namely PMIC, UART, I2C, GPIO, SD card, QSPI Flash, eMMC and Ethernet.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>

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/jh7110-milkv-mars.dts

+// SPDX-License-Identifier: GPL-2.0 OR MIT
+/*
+ * Copyright (C) 2023 Jisheng Zhang <jszhang@kernel.org>
+ */
+
+/dts-v1/;
+#include "jh7110-common.dtsi"
+
+/ {
+	model = "Milk-V Mars";
+	compatible = "milkv,mars", "starfive,jh7110";
+};
+
+&gmac0 {
+	starfive,tx-use-rgmii-clk;
+	assigned-clocks = <&aoncrg JH7110_AONCLK_GMAC0_TX>;
+	assigned-clock-parents = <&aoncrg JH7110_AONCLK_GMAC0_RMII_RTX>;
+};
+
+
+&phy0 {
+	motorcomm,tx-clk-adj-enabled;
+	motorcomm,tx-clk-10-inverted;
+	motorcomm,tx-clk-100-inverted;
+	motorcomm,tx-clk-1000-inverted;
+	motorcomm,rx-clk-drv-microamp = <3970>;
+	motorcomm,rx-data-drv-microamp = <2910>;
+	rx-internal-delay-ps = <1500>;
+	tx-internal-delay-ps = <1500>;
+};