drm/amd/display: Reduce height of visual confirm on right side.

[Why]
right side visual confirm is too thick due to it is 4 times of
left side (16 lines).

[How]
Change factor from 4 to 2.
Signed-off-by: NYongqiang Sun <yongqiang.sun@amd.com>
Acked-by: NAurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dcn10/dcn10_dpp_dscl.c

@@ -656,7 +656,7 @@ static void dpp1_dscl_set_recout(
 			 RECOUT_WIDTH, recout->width,
 		/* Number of RECOUT vertical lines */
 			 RECOUT_HEIGHT, recout->height
-			 - visual_confirm_on * 4 * (dpp->base.inst + 1));
+			 - visual_confirm_on * 2 * (dpp->base.inst + 1));
 }
 
 /* Main function to program scaler and line buffer in manual scaling mode */