arm: rmobile: Add HopeRun HiHope RZ/G2M board support

The HiHope RZ/G2M board from HopeRun consists of main board
(HopeRun HiHope RZ/G2M main board) and sub board(HopeRun
HiHope RZ/G2M sub board). The HiHope RZ/G2M sub board sits
below the HiHope RZ/G2M main board.

This patch adds the required board support to boot HopeRun HiHope
RZ/G2M board.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
diff --git a/include/configs/hihope-rzg2.h b/include/configs/hihope-rzg2.h
new file mode 100644
index 0000000..68a5117
--- /dev/null
+++ b/include/configs/hihope-rzg2.h
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * include/configs/hihope-rzg2.h
+ *     This file is HOPERUN HiHope RZ/G2 board configuration.
+ *
+ * Copyright (C) 2020 Renesas Electronics Corporation
+ */
+
+#ifndef __HIHOPE_RZG2_H
+#define __HIHOPE_RZG2_H
+
+#include "rcar-gen3-common.h"
+
+/* Ethernet RAVB */
+#define CONFIG_BITBANGMII_MULTI
+
+/* Generic Timer Definitions (use in assembler source) */
+#define COUNTER_FREQUENCY	0xFE502A	/* 16.66MHz from CPclk */
+
+#endif /* __HIHOPE_RZG2_H */