drm/rockchip: vop: fix window origin calculation

VOP_WINx_DSP_ST does not require subtracting 1 from the values written to
it. It actually causes the screen to be shifted by one pixel.

Signed-off-by: Mark Yao <mark.yao@rock-chips.com>
Tested-by: Yakir Yang <ykk@rock-chips.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Dominik Behr <dbehr@chromium.org>
Signed-off-by: Mark Yao <mark.yao@rock-chips.com>

drivers/gpu/drm/rockchip/rockchip_drm_vop.c

@@ -959,8 +959,8 @@ static int vop_update_plane_event(struct drm_plane *plane,
 	val = (dest.y2 - dest.y1 - 1) << 16;
 	val |= (dest.x2 - dest.x1 - 1) & 0xffff;
 	VOP_WIN_SET(vop, win, dsp_info, val);
-	val = (dsp_sty - 1) << 16;
-	val |= (dsp_stx - 1) & 0xffff;
+	val = dsp_sty << 16;
+	val |= dsp_stx & 0xffff;
 	VOP_WIN_SET(vop, win, dsp_st, val);
 	VOP_WIN_SET(vop, win, rb_swap, rb_swap);