mtd: m25p80: Add missing m25p80 flash merge

Added m25p80 flash merge which is missing on below
merge commit
"Merge tag 'v3.12' into master-next"
(sha1: cd30bed1eb9cddb9bd24c0fcd13bdbba6373ac1f)

Signed-off-by: Punnaiah Choudary Kalluri <punnaia@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>