drm: rockchip: add missing registers for RK3188

Add dither_up, dsp_lut_en and data_blank registers to enable their
respective functionality for RK3188's VOP.
While at that also fix .dsp_blank register which is (only) set with
BIT24 (same as RK3066)
Signed-off-by: Alex Bee <knaerzche@gmail.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20210528130554.72191-3-knaerzche@gmail.com

drivers/gpu/drm/rockchip/rockchip_vop_reg.c

@@ -511,7 +511,10 @@ static const struct vop_common rk3188_common = {
 	.dither_down_sel = VOP_REG(RK3188_DSP_CTRL0, 0x1, 27),
 	.dither_down_en = VOP_REG(RK3188_DSP_CTRL0, 0x1, 11),
 	.dither_down_mode = VOP_REG(RK3188_DSP_CTRL0, 0x1, 10),
-	.dsp_blank = VOP_REG(RK3188_DSP_CTRL1, 0x3, 24),
+	.dsp_blank = VOP_REG(RK3188_DSP_CTRL1, 0x1, 24),
+	.dither_up = VOP_REG(RK3188_DSP_CTRL0, 0x1, 9),
+	.dsp_lut_en = VOP_REG(RK3188_SYS_CTRL, 0x1, 28),
+	.data_blank = VOP_REG(RK3188_DSP_CTRL1, 0x1, 25),
 };
 
 static const struct vop_win_data rk3188_vop_win_data[] = {