board: MCR3000: replace mtd->priv by mtd_to_nand()

Since commit 17cb4b8f327eb ("mtd: nand: Add+use mtd_to/from_nand and
nand_get/set_controller_data"), mtd_to_nand() has to be used instead
of mtd->priv

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
1 file changed