rockchip: rv1126: Enable fdtoverlay support

Add fdtoverlay_addr_r and enable OF_LIBFDT_OVERLAY for the
use of DT overlay in RV1126.

Signed-off-by: Jagan Teki <jagan@edgeble.ai>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/arch/arm/mach-rockchip/Kconfig b/arch/arm/mach-rockchip/Kconfig
index 49da93d..a279582 100644
--- a/arch/arm/mach-rockchip/Kconfig
+++ b/arch/arm/mach-rockchip/Kconfig
@@ -359,6 +359,7 @@
 	select PMIC_RK8XX
 	select BOARD_LATE_INIT
 	imply ROCKCHIP_COMMON_BOARD
+	imply OF_LIBFDT_OVERLAY
 	imply TPL_DM
 	imply TPL_LIBCOMMON_SUPPORT
 	imply TPL_LIBGENERIC_SUPPORT