arm64: dts: meson: add g12a x96 max board

Add the G12a (S905X2) based X96 Max board[1].

There is no branding for the manufacturer anywhere on the product, so it
took some digging[2] to find the manufacturer.  But since there's
nothing about the maker on the product I've left it out of the DT name
because 1) nobody will know that name and 2) keeps the DT filename
shorter.

[1] https://www.cnx-software.com/2018/09/25/x96-max-amlogic-s905x2-tv-box/
[2] https://fccid.io/2AI6D-X96MAX

Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>

arch/arm64/boot/dts/amlogic/Makefile

@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 dtb-$(CONFIG_ARCH_MESON) += meson-axg-s400.dtb
 dtb-$(CONFIG_ARCH_MESON) += meson-g12a-u200.dtb
+dtb-$(CONFIG_ARCH_MESON) += meson-g12a-x96-max.dtb
 dtb-$(CONFIG_ARCH_MESON) += meson-gxbb-nanopi-k2.dtb
 dtb-$(CONFIG_ARCH_MESON) += meson-gxbb-nexbox-a95x.dtb
 dtb-$(CONFIG_ARCH_MESON) += meson-gxbb-odroidc2.dtb

arch/arm64/boot/dts/amlogic/meson-g12a-x96-max.dts

@@ -0,0 +1,28 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+/*
+ * Copyright (c) 2018 BayLibre SAS. All rights reserved.
+ */
+
+/dts-v1/;
+
+#include "meson-g12a.dtsi"
+
+/ {
+	compatible = "amediatech,x96-max", "amlogic,u200", "amlogic,g12a";
+	model = "Shenzhen Amediatech Technology Co., Ltd X96 Max";
+
+	aliases {
+		serial0 = &uart_AO;
+	};
+	chosen {
+		stdout-path = "serial0:115200n8";
+	};
+	memory@0 {
+		device_type = "memory";
+		reg = <0x0 0x0 0x0 0x40000000>;
+	};
+};
+
+&uart_AO {
+	status = "okay";
+};