rockchip: arm64: rk3399: add SPL support

Add SPL support for rk3399, default with of-platdata enabled.

Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Drop Kconfig changes to fix build error:
Signed-off-by: Simon Glass <sjg@chromium.org>
3 files changed