arm: dts: rmobile: r8a774a1: Synchronize DTs with Linux 5.10

DTS files apart from r8a774a1-hihope-rzg2m-u-boot.dts and
r8a774a1-u-boot.dtsi have been imported from linux 5.10
commit 2c85ebc57b3e1817 ("Linux 5.10").

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
diff --git a/arch/arm/dts/r8a774a1-hihope-rzg2m-ex.dts b/arch/arm/dts/r8a774a1-hihope-rzg2m-ex.dts
new file mode 100644
index 0000000..f0e4a1f
--- /dev/null
+++ b/arch/arm/dts/r8a774a1-hihope-rzg2m-ex.dts
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Device Tree Source for the HiHope RZ/G2M Rev.3.0/4.0 connected to
+ * sub board
+ *
+ * Copyright (C) 2021 Renesas Electronics Corp.
+ */
+
+#include "r8a774a1-hihope-rzg2m.dts"
+#include "hihope-rzg2-ex.dtsi"
+
+/ {
+	model = "HopeRun HiHope RZ/G2M with sub board";
+	compatible = "hoperun,hihope-rzg2-ex", "hoperun,hihope-rzg2m",
+		     "renesas,r8a774a1";
+};
+
+/* SW43 should be OFF, if in ON state SATA port will be activated */
+&pciec1 {
+	status = "okay";
+};