drm/rockchip: vop: move write_relaxed flags to vop register

drm/rockchip: vop: move write_relaxed flags to vop register

Since the drm atomic framework, only a small part of the vop
register needs sync write, Currently seems only following registers
need sync write:
   cfg_done, standby and interrupt related register.

All ctrl registers are using the sync write method that is
inefficient, hardcode the write_relaxed flags to vop registers,
then can only do synchronize write for those actual needed register.

Signed-off-by: Mark Yao <[email protected]>
Tested-by: Heiko Stuebner <[email protected]>
Reviewed-by: Jeffy Chen <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]