drm: rockchip: add missing registers for RK3066

Add dither_up, dsp_lut_en and data_blank registers to enable their
respective functionality for RK3066's VOP.

While at that also fix .rb_swap and .format registers for all windows,
which have to be set though RK3066_SYS_CTRL1 register.
Also remove .scl from win1: Scaling is only supported on the primary
plane.

Signed-off-by: Alex Bee <knaerzche@gmail.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20210528130554.72191-4-knaerzche@gmail.com