mtd: atmel_nand: use devm_xxx gpio kzalloc, gpio and ioremap

mtd: atmel_nand: use devm_xxx gpio kzalloc, gpio and ioremap

this will allow to simply the error and remove path

Cc: [email protected]
Cc: Nicolas Ferre <[email protected]>
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <[email protected]>
[[email protected]: fix checkpatch warnings and rebase to latest mtd git tree]
[[email protected]: replace devm_request_and_ioremap with devm_ioremap_resource]
Signed-off-by: Josh Wu <[email protected]>
Signed-off-by: Artem Bityutskiy <[email protected]>
Signed-off-by: David Woodhouse <[email protected]>