arm64: dts: rockchip: Add RK3399 ROCK Pi 4A+ board

ROCK Pi 4A+ board is the successor of ROCK Pi 4A board.

Differences to the original version are
- has RK3399 OP1 SoC revision
- has eMMC (16 or 32 GB) soldered on board (no changes required,
  since it is enabled in rk3399-rock-pi-4.dtsi)
- dev boards have SPI flash soldered, but as per manufacturer response,
  this won't be the case for mass production boards
Signed-off-by: Alex Bee <knaerzche@gmail.com>
Link: https://lore.kernel.org/r/20210618181256.27992-3-knaerzche@gmail.comSigned-off-by: Heiko Stuebner <heiko@sntech.de>

arch/arm64/boot/dts/rockchip/Makefile

@@ -45,6 +45,7 @@ dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3399-roc-pc.dtb
 dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3399-roc-pc-mezzanine.dtb
 dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3399-roc-pc-plus.dtb
 dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3399-rock-pi-4a.dtb
+dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3399-rock-pi-4a-plus.dtb
 dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3399-rock-pi-4b.dtb
 dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3399-rock-pi-4c.dtb
 dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3399-rock960.dtb

arch/arm64/boot/dts/rockchip/rk3399-rock-pi-4a-plus.dts

+// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+/*
+ * Copyright (c) 2019 Akash Gajjar <Akash_Gajjar@mentor.com>
+ * Copyright (c) 2019 Pragnesh Patel <Pragnesh_Patel@mentor.com>
+ */
+
+/dts-v1/;
+#include "rk3399-rock-pi-4.dtsi"
+#include "rk3399-op1-opp.dtsi"
+
+/ {
+	model = "Radxa ROCK Pi 4A+";
+	compatible = "radxa,rockpi4a-plus", "radxa,rockpi4", "rockchip,rk3399";
+};