ARM: dts: mstar: Add a dts for Miyoo Mini

Miyoo has released a portable retro games machine based
on the SigmaStar SSD202D. Add the initial device tree
for this machine. Just enough to get to an initramfs
shell.

Link: http://linux-chenxing.org/infinity2/miyoomini/
Signed-off-by: Daniel Palmer <[e-mail]>

arch/arm/boot/dts/Makefile

···
 dtb-$(CONFIG_ARCH_MILBEAUT) += milbeaut-m10v-evb.dtb
 dtb-$(CONFIG_ARCH_MSTARV7) += \
 	mstar-infinity-msc313-breadbee_crust.dtb \
+	mstar-infinity2m-ssd202d-miyoo-mini.dtb \
 	mstar-infinity2m-ssd202d-wirelesstag-ido-sbc2d06-v1b-22w.dtb \
 	mstar-infinity2m-ssd202d-ssd201htv2.dtb \
 	mstar-infinity2m-ssd202d-unitv2.dtb \

arch/arm/boot/dts/mstar-infinity2m-ssd202d-miyoo-mini.dts

···
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2021 thingy.jp.
+ * Author: Daniel Palmer <[e-mail]>
+ */
+
+/dts-v1/;
+#include "mstar-infinity2m-ssd202d.dtsi"
+
+/ {
+	model = "Miyoo Mini";
+	compatible = "miyoo,miyoo-mini", "mstar,infinity2m";
+
+	aliases {
+		serial0 = &pm_uart;
+	};
+
+	chosen {
+		stdout-path = "serial0:115200n8";
+	};
+};
+
+&pm_uart {
+	status = "okay";
+};