OMAP: DSS2: add read_edid() to omap_dss_driver struct

read_edid() can be used to get the EDID information from the display.
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@ti.com>

include/video/omapdss.h

@@ -622,6 +622,8 @@ struct omap_dss_driver {
 
 	int (*set_wss)(struct omap_dss_device *dssdev, u32 wss);
 	u32 (*get_wss)(struct omap_dss_device *dssdev);
+
+	int (*read_edid)(struct omap_dss_device *dssdev, u8 *buf, int len);
 };
 
 int omap_dss_register_driver(struct omap_dss_driver *);