configs: rockchip: imply OF_LIBFDT_OVERLAY for rk3308 and rk3328

for rk3308, all defconfigs have CONFIG_OF_LIBFDT_OVERLAY=y, so enable it
by default.

for rk3328, any defconfig doesn't have it. but there is no strong reason
not to enable it. at least it's required for ROCK Pi E.

Signed-off-by: FUKAUMI Naoki <naoki@radxa.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
4 files changed