drm/edid: detect basic audio in all CEA extensions

Convert drm_find_cea_extension() to EDID block iterator in basic audio
detection. Detect basic audio in all CEA extensions.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/59481d0397de4b91b3e6ea665882334e92538f40.1651569697.git.jani.nikula@intel.com

drivers/gpu/drm/drm_edid.c

@@ -5112,17 +5112,21 @@ EXPORT_SYMBOL(drm_detect_hdmi_monitor);
  */
 bool drm_detect_monitor_audio(const struct edid *edid)
 {
+	struct drm_edid_iter edid_iter;
 	const struct cea_db *db;
 	struct cea_db_iter iter;
 	const u8 *edid_ext;
 	bool has_audio = false;
 
-	edid_ext = drm_find_cea_extension(edid);
-	if (!edid_ext)
-		goto end;
-
-	has_audio = (edid_ext[0] == CEA_EXT &&
-		    (edid_ext[3] & EDID_BASIC_AUDIO) != 0);
+	drm_edid_iter_begin(edid, &edid_iter);
+	drm_edid_iter_for_each(edid_ext, &edid_iter) {
+		if (edid_ext[0] == CEA_EXT) {
+			has_audio = edid_ext[3] & EDID_BASIC_AUDIO;
+			if (has_audio)
+				break;
+		}
+	}
+	drm_edid_iter_end(&edid_iter);
 
 	if (has_audio) {
 		DRM_DEBUG_KMS("Monitor has basic audio support\n");