arm64: dts: renesas: Add HiHope RZ/G2N sub board support

The HiHope RZ/G2N sub board sits below the HiHope RZ/G2N main board.
Signed-off-by: Biju Das <biju.das@bp.renesas.com>
Link: https://lore.kernel.org/r/1569831527-1250-6-git-send-email-biju.das@bp.renesas.comSigned-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

arch/arm64/boot/dts/renesas/Makefile

@@ -2,6 +2,7 @@
 dtb-$(CONFIG_ARCH_R8A774A1) += r8a774a1-hihope-rzg2m.dtb
 dtb-$(CONFIG_ARCH_R8A774A1) += r8a774a1-hihope-rzg2m-ex.dtb
 dtb-$(CONFIG_ARCH_R8A774B1) += r8a774b1-hihope-rzg2n.dtb
+dtb-$(CONFIG_ARCH_R8A774B1) += r8a774b1-hihope-rzg2n-ex.dtb
 dtb-$(CONFIG_ARCH_R8A774C0) += r8a774c0-cat874.dtb r8a774c0-ek874.dtb
 dtb-$(CONFIG_ARCH_R8A7795) += r8a7795-salvator-x.dtb r8a7795-h3ulcb.dtb
 dtb-$(CONFIG_ARCH_R8A7795) += r8a7795-h3ulcb-kf.dtb

arch/arm64/boot/dts/renesas/r8a774b1-hihope-rzg2n-ex.dts

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Device Tree Source for the HiHope RZ/G2N sub board
+ *
+ * Copyright (C) 2019 Renesas Electronics Corp.
+ */
+
+#include "r8a774b1-hihope-rzg2n.dts"
+#include "hihope-rzg2-ex.dtsi"
+
+/ {
+	model = "HopeRun HiHope RZ/G2N with sub board";
+	compatible = "hoperun,hihope-rzg2-ex", "hoperun,hihope-rzg2n",
+		     "renesas,r8a774b1";
+};