drm/edid: sunset the old unused cea data block iterators

All CTA data block iteration has now been converted to the new cea db
iterators.

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/a5b35ed0e711bd874f76ae87ee0b70150d0a77c4.1651569697.git.jani.nikula@intel.com

drivers/gpu/drm/drm_edid.c

@@ -4349,48 +4349,6 @@ cea_revision(const u8 *cea)
 	return cea[1];
 }
 
-static int
-cea_db_offsets(const u8 *cea, int *start, int *end)
-{
-	/* DisplayID CTA extension blocks and top-level CEA EDID
-	 * block header definitions differ in the following bytes:
-	 *   1) Byte 2 of the header specifies length differently,
-	 *   2) Byte 3 is only present in the CEA top level block.
-	 *
-	 * The different definitions for byte 2 follow.
-	 *
-	 * DisplayID CTA extension block defines byte 2 as:
-	 *   Number of payload bytes
-	 *
-	 * CEA EDID block defines byte 2 as:
-	 *   Byte number (decimal) within this block where the 18-byte
-	 *   DTDs begin. If no non-DTD data is present in this extension
-	 *   block, the value should be set to 04h (the byte after next).
-	 *   If set to 00h, there are no DTDs present in this block and
-	 *   no non-DTD data.
-	 */
-	if (cea[0] == DATA_BLOCK_CTA) {
-		/*
-		 * for_each_displayid_db() has already verified
-		 * that these stay within expected bounds.
-		 */
-		*start = 3;
-		*end = *start + cea[2];
-	} else if (cea[0] == CEA_EXT) {
-		/* Data block offset in CEA extension block */
-		*start = 4;
-		*end = cea[2];
-		if (*end == 0)
-			*end = 127;
-		if (*end < 4 || *end > 127)
-			return -ERANGE;
-	} else {
-		return -EOPNOTSUPP;
-	}
-
-	return 0;
-}
-
 /*
  * CTA Data Block iterator.
  *
@@ -4643,9 +4601,6 @@ static bool cea_db_is_hdmi_hdr_metadata_block(const void *db)
 		cea_db_payload_len(db) >= 3;
 }
 
-#define for_each_cea_db(cea, i, start, end) \
-	for ((i) = (start); (i) < (end) && (i) + cea_db_payload_len(&(cea)[(i)]) < (end); (i) += cea_db_payload_len(&(cea)[(i)]) + 1)
-
 static void drm_parse_y420cmdb_bitmap(struct drm_connector *connector,
 				      const u8 *db)
 {