As rk3308 is a aarch64 based soc, we only let it run spl on aarch64 excution state. But for u-boot stage, it may run on aarch32 or aarch64 state. Change-Id: I592375aef19a35f10555f7c5b991445cf02c4543 Signed-off-by: Andy Yan <andy.yan@rock-chips.com>