kernel: fix compiler warning in mtdsplit_minor.c under 4.4

When mtdsplit_minor.c is compiled under Linux 4.4, the compiler
drops the following warning:

    CC      drivers/mtd/mtdsplit/mtdsplit_minor.o
  drivers/mtd/mtdsplit/mtdsplit_minor.c:106:14: warning: initialization from incompatible pointer type [-Wincompatible-pointer-types]
    .parse_fn = mtdsplit_parse_minor,
                ^
  drivers/mtd/mtdsplit/mtdsplit_minor.c:106:14: note: (near initialization for 'mtdsplit_minor_parser.parse_fn')

The second parameter of the parser function must not have a 'const'
qualifier in 4.4. The 001-mtdsplit_backport.patch removes the qualifier
from other partition parsers. Update it to handle mtdsplit_minor.c as
well.

Signed-off-by: Gabor Juhos <juhosg@freemail.hu>

target/linux/generic/pending-4.4/001-mtdsplit_backport.patch

@@ -140,3 +140,14 @@
  {
  	struct wrgg03_header hdr;
  	size_t hdr_len, retlen, kernel_ent_size;
+--- a/drivers/mtd/mtdsplit/mtdsplit_minor.c
++++ b/drivers/mtd/mtdsplit/mtdsplit_minor.c
+@@ -49,7 +49,7 @@ struct minor_header {
+ };
+ 
+ static int mtdsplit_parse_minor(struct mtd_info *master,
+-				const struct mtd_partition **pparts,
++				struct mtd_partition **pparts,
+ 				struct mtd_part_parser_data *data)
+ {
+ 	struct minor_header hdr;