ARM: dts: renesas: Switch to using upstream DT on Renesas R8A779H0 V4M

Enable OF_UPSTREAM to use upstream DT and add renesas/ prefix to the
DEFAULT_DEVICE_TREE. And thereby directly build DTB from dts/upstream/src/
including *-u-boot.dtsi files from arch/$(ARCH)/dts/ directory.

This patch finalizes OF_UPSTREAM conversion of R8A779H0 V4M which DTs
landed in Linux 6.9 .

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
Acked-by: Sumit Garg <sumit.garg@linaro.org>
diff --git a/configs/r8a779h0_grayhawk_defconfig b/configs/r8a779h0_grayhawk_defconfig
index 6bd872f..a986a09 100644
--- a/configs/r8a779h0_grayhawk_defconfig
+++ b/configs/r8a779h0_grayhawk_defconfig
@@ -5,7 +5,7 @@
 CONFIG_ENV_SIZE=0x20000
 CONFIG_ENV_OFFSET=0xFFFE0000
 CONFIG_DM_GPIO=y
-CONFIG_DEFAULT_DEVICE_TREE="r8a779h0-gray-hawk"
+CONFIG_DEFAULT_DEVICE_TREE="renesas/r8a779h0-gray-hawk-single"
 CONFIG_RCAR_GEN4=y
 CONFIG_TARGET_GRAYHAWK=y
 CONFIG_SYS_MONITOR_LEN=1048576
@@ -39,7 +39,6 @@
 CONFIG_CMD_FAT=y
 CONFIG_CMD_FS_GENERIC=y
 CONFIG_OF_CONTROL=y
-# CONFIG_OF_UPSTREAM is not set
 CONFIG_ENV_IS_IN_MMC=y
 CONFIG_SYS_RELOC_GD_ENV_ADDR=y
 CONFIG_SYS_MMC_ENV_PART=2