sunxi: imply CONFIG_OF_LIBFDT_OVERLAY

fdt overlay support is useful for all sunxi boards, enable per default
and remove it from sunxi defconfigs.

Signed-off-by: Andre Heider <a.heider@gmail.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Jagan Teki <jagan@openedev.com>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index f6d57f5..73fbd54 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -746,6 +746,7 @@
 	select USE_TINY_PRINTF
 	imply CMD_GPT
 	imply FAT_WRITE
+	imply OF_LIBFDT_OVERLAY
 	imply PRE_CONSOLE_BUFFER
 	imply SPL_GPIO_SUPPORT
 	imply SPL_LIBCOMMON_SUPPORT