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/configs/hihope_rzg2_defconfig b/configs/hihope_rzg2_defconfig
new file mode 100644
index 0000000..bc40445
--- /dev/null
+++ b/configs/hihope_rzg2_defconfig
@@ -0,0 +1,82 @@
+CONFIG_ARM=y
+CONFIG_ARCH_CPU_INIT=y
+CONFIG_ARCH_RMOBILE=y
+CONFIG_SYS_TEXT_BASE=0x50000000
+CONFIG_ENV_SIZE=0x20000
+CONFIG_ENV_OFFSET=0xFFFE0000
+CONFIG_DM_GPIO=y
+CONFIG_RCAR_GEN3=y
+CONFIG_TARGET_HIHOPE_RZG2=y
+# CONFIG_SPL is not set
+CONFIG_DEFAULT_DEVICE_TREE="r8a774a1-hihope-rzg2m-u-boot"
+CONFIG_FIT=y
+CONFIG_SUPPORT_RAW_INITRD=y
+CONFIG_USE_BOOTARGS=y
+CONFIG_BOOTARGS="root=/dev/nfs rw nfsroot=192.168.0.1:/export/rfs ip=192.168.0.20"
+CONFIG_DEFAULT_FDT_FILE="r8a774a1-hihope-rzg2m.dtb"
+# CONFIG_BOARD_EARLY_INIT_F is not set
+CONFIG_HUSH_PARSER=y
+CONFIG_CMD_BOOTZ=y
+CONFIG_CMD_GPIO=y
+CONFIG_CMD_I2C=y
+CONFIG_CMD_MMC=y
+CONFIG_CMD_PART=y
+CONFIG_CMD_SPI=y
+CONFIG_CMD_USB=y
+CONFIG_CMD_DHCP=y
+CONFIG_CMD_MII=y
+CONFIG_CMD_PING=y
+CONFIG_CMD_EXT2=y
+CONFIG_CMD_EXT4=y
+CONFIG_CMD_EXT4_WRITE=y
+CONFIG_CMD_FAT=y
+CONFIG_CMD_FS_GENERIC=y
+CONFIG_OF_CONTROL=y
+CONFIG_OF_LIST="r8a774a1-hihope-rzg2m-u-boot"
+CONFIG_MULTI_DTB_FIT_LZO=y
+CONFIG_MULTI_DTB_FIT_USER_DEFINED_AREA=y
+CONFIG_ENV_OVERWRITE=y
+CONFIG_ENV_IS_IN_MMC=y
+CONFIG_SYS_RELOC_GD_ENV_ADDR=y
+CONFIG_SYS_MMC_ENV_DEV=1
+CONFIG_SYS_MMC_ENV_PART=2
+CONFIG_VERSION_VARIABLE=y
+CONFIG_REGMAP=y
+CONFIG_SYSCON=y
+CONFIG_CLK=y
+CONFIG_CLK_RENESAS=y
+CONFIG_GPIO_HOG=y
+CONFIG_RCAR_GPIO=y
+CONFIG_DM_PCA953X=y
+CONFIG_DM_I2C=y
+CONFIG_SYS_I2C_RCAR_I2C=y
+CONFIG_SYS_I2C_RCAR_IIC=y
+CONFIG_DM_MMC=y
+CONFIG_MMC_IO_VOLTAGE=y
+CONFIG_MMC_UHS_SUPPORT=y
+CONFIG_MMC_HS400_SUPPORT=y
+CONFIG_RENESAS_SDHI=y
+CONFIG_DM_SPI_FLASH=y
+CONFIG_SPI_FLASH_BAR=y
+CONFIG_SPI_FLASH_WINBOND=y
+CONFIG_SPI_FLASH_USE_4K_SECTORS=y
+CONFIG_BITBANGMII=y
+CONFIG_PHY_REALTEK=y
+CONFIG_DM_ETH=y
+CONFIG_RENESAS_RAVB=y
+CONFIG_DM_REGULATOR=y
+CONFIG_DM_REGULATOR_FIXED=y
+CONFIG_DM_REGULATOR_GPIO=y
+CONFIG_SCIF_CONSOLE=y
+CONFIG_SPI=y
+CONFIG_DM_SPI=y
+CONFIG_RENESAS_RPC_SPI=y
+CONFIG_TEE=y
+CONFIG_OPTEE=y
+CONFIG_USB=y
+CONFIG_DM_USB=y
+CONFIG_USB_XHCI_HCD=y
+CONFIG_USB_EHCI_HCD=y
+CONFIG_USB_EHCI_GENERIC=y
+CONFIG_USB_STORAGE=y
+CONFIG_OF_LIBFDT_OVERLAY=y