drm/rockchip: vop2: Add write mask for VP config done

The write mask bit is used to make sure when writing
config done bit for one VP will not overwrite the other.

Unfortunately, the write mask bit is missing on
rk3566/8, that means when we write to these bits,
it will not take any effect.

We need this to make the vop work properly after
rk3566/8 variants.

Signed-off-by: Andy Yan <andy.yan@rock-chips.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20231211115752.1785013-1-andyshrk@163.com