OMAP: DSS2: Add method for querying display dimensions from DSS drivers

Add get_dimensions() to struct omap_dss_driver. Use the call, if supported
by the driver, in OMAPFB.

Signed-off-by: Jani Nikula <ext-jani.1.nikula@nokia.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
diff --git a/include/video/omapdss.h b/include/video/omapdss.h
index 53ca97c..f078929 100644
--- a/include/video/omapdss.h
+++ b/include/video/omapdss.h
@@ -505,6 +505,8 @@
 
 	void (*get_resolution)(struct omap_dss_device *dssdev,
 			u16 *xres, u16 *yres);
+	void (*get_dimensions)(struct omap_dss_device *dssdev,
+			u32 *width, u32 *height);
 	int (*get_recommended_bpp)(struct omap_dss_device *dssdev);
 
 	int (*check_timings)(struct omap_dss_device *dssdev,