OMAP4: DSS2: HDMI: Dispc gamma enable set/reset function for TV.

Adding function to reset/set gamma table bit for TV interface, currently
only support for disabled is added.

Signed-off-by: Mythri P K <mythripk@ti.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
diff --git a/drivers/video/omap2/dss/dss.h b/drivers/video/omap2/dss/dss.h
index eb05d39..ab20270 100644
--- a/drivers/video/omap2/dss/dss.h
+++ b/drivers/video/omap2/dss/dss.h
@@ -370,6 +370,7 @@
 void dispc_set_channel_out(enum omap_plane plane,
 		enum omap_channel channel_out);
 
+void dispc_enable_gamma_table(bool enable);
 int dispc_setup_plane(enum omap_plane plane,
 		      u32 paddr, u16 screen_width,
 		      u16 pos_x, u16 pos_y,