mtd: OneNAND: Change dependency of ARCH_EXYNOS4

This patch updates EXYNOS4 OneNAND support according to the change of
ARCH name, EXYNOS4.

Cc: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
1 file changed