OMAPDSS: DISPC: Configure input and output sizes for writeback

Writeback uses the WB_PICTURE_SIZE register to define the size of the content
written to memory, this is the output of the scaler. It uses the WB_SIZE
register to define the size of the content coming from the overlay/manager to
which it is connected, this is the input to the scaler. This naming is different
as compared to overlays.

Add checks for writeback in dispc_ovl_set_input_size() and
dispc_ovl_set_output_size() to write to the correct registers.

Signed-off-by: Archit Taneja <archit@ti.com>
diff --git a/drivers/video/omap2/dss/dispc.c b/drivers/video/omap2/dss/dispc.c
index b1b9e3f..b9e53b3 100644
--- a/drivers/video/omap2/dss/dispc.c
+++ b/drivers/video/omap2/dss/dispc.c
@@ -719,7 +719,7 @@
 {
 	u32 val = FLD_VAL(height - 1, 26, 16) | FLD_VAL(width - 1, 10, 0);
 
-	if (plane == OMAP_DSS_GFX)
+	if (plane == OMAP_DSS_GFX || plane == OMAP_DSS_WB)
 		dispc_write_reg(DISPC_OVL_SIZE(plane), val);
 	else
 		dispc_write_reg(DISPC_OVL_PICTURE_SIZE(plane), val);
@@ -734,7 +734,10 @@
 
 	val = FLD_VAL(height - 1, 26, 16) | FLD_VAL(width - 1, 10, 0);
 
-	dispc_write_reg(DISPC_OVL_SIZE(plane), val);
+	if (plane == OMAP_DSS_WB)
+		dispc_write_reg(DISPC_OVL_PICTURE_SIZE(plane), val);
+	else
+		dispc_write_reg(DISPC_OVL_SIZE(plane), val);
 }
 
 static void dispc_ovl_set_zorder(enum omap_plane plane,