OMAPDSS: DISPC: Configure writeback specific parameters in dispc_wb_setup()

Configure some of the writeback specific parameters in dispc_wb_setup(). The
writeback parameters configured are:

truncation: This needs to be set if the color depth input to writeback is more
than the color depth of the color mode we want to store in memory.

writeback mode: This configures whether we want to use writeback in mem to mem
or capture mode. This information will be directly passed by APPLY later.

Signed-off-by: Archit Taneja <archit@ti.com>
diff --git a/drivers/video/omap2/dss/dss.h b/drivers/video/omap2/dss/dss.h
index 3f9208e..8677f51 100644
--- a/drivers/video/omap2/dss/dss.h
+++ b/drivers/video/omap2/dss/dss.h
@@ -488,7 +488,7 @@
 
 void dispc_wb_set_channel_in(enum dss_writeback_channel channel);
 int dispc_wb_setup(const struct omap_dss_writeback_info *wi,
-		const struct omap_video_timings *timings);
+		bool mem_to_mem, const struct omap_video_timings *timings);
 
 /* VENC */
 #ifdef CONFIG_OMAP2_DSS_VENC