mtd: add 'const' qualifier to a couple of register functions

'mtd_device_parse_register()' and 'parse_mtd_partitions()' functions accept a
an array of character pointers. These functions modify neither the pointers nor
the characters they point to. The characters are actually names of the MTD
parsers.

At the moment, the argument type is 'const char **', which means that only the
names of the parsers are constant. Let's turn the argument type into 'const
char * const *', which means that both names and the pointers which point to
them are constant.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

drivers/mtd/mtdpart.c

@@ -720,7 +720,7 @@ static const char *default_mtd_part_types[] = {
  * o a positive number of found partitions, in which case on exit @pparts will
  *   point to an array containing this number of &struct mtd_info objects.
  */
-int parse_mtd_partitions(struct mtd_info *master, const char **types,
+int parse_mtd_partitions(struct mtd_info *master, const char *const *types,
 			 struct mtd_partition **pparts,
 			 struct mtd_part_parser_data *data)
 {