drm/bridge: lt9611: simplify video timings programming

Inline calculated values to simplify the calculation in
lt9611_mipi_video_setup().
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230118081658.2198520-11-dmitry.baryshkov@linaro.org

drivers/gpu/drm/bridge/lontium-lt9611.c

@@ -155,12 +155,12 @@ static void lt9611_mipi_video_setup(struct lt9611 *lt9611,
 	hactive = mode->hdisplay;
 	hsync_len = mode->hsync_end - mode->hsync_start;
 	hfront_porch = mode->hsync_start - mode->hdisplay;
-	hsync_porch = hsync_len + mode->htotal - mode->hsync_end;
+	hsync_porch = mode->htotal - mode->hsync_start;
 
 	vactive = mode->vdisplay;
 	vsync_len = mode->vsync_end - mode->vsync_start;
 	vfront_porch = mode->vsync_start - mode->vdisplay;
-	vsync_porch = vsync_len + mode->vtotal - mode->vsync_end;
+	vsync_porch = mode->vtotal - mode->vsync_start;
 
 	regmap_write(lt9611->regmap, 0x830d, (u8)(v_total / 256));
 	regmap_write(lt9611->regmap, 0x830e, (u8)(v_total % 256));