drm/edid: constify edid quirk list

No reason not to be const.
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1482923186-22430-1-git-send-email-jani.nikula@intel.com

drivers/gpu/drm/drm_edid.c

@@ -91,7 +91,7 @@ struct detailed_mode_closure {
 #define LEVEL_GTF2	2
 #define LEVEL_CVT	3
 
-static struct edid_quirk {
+static const struct edid_quirk {
 	char vendor[4];
 	int product_id;
 	u32 quirks;
@@ -1478,7 +1478,7 @@ EXPORT_SYMBOL(drm_edid_duplicate);
  *
  * Returns true if @vendor is in @edid, false otherwise
  */
-static bool edid_vendor(struct edid *edid, char *vendor)
+static bool edid_vendor(struct edid *edid, const char *vendor)
 {
 	char edid_vendor[3];
 
@@ -1498,7 +1498,7 @@ static bool edid_vendor(struct edid *edid, char *vendor)
  */
 static u32 edid_get_quirks(struct edid *edid)
 {
-	struct edid_quirk *quirk;
+	const struct edid_quirk *quirk;
 	int i;
 
 	for (i = 0; i < ARRAY_SIZE(edid_quirk_list); i++) {