ARM: S3C24XX: Removed unneeded dependency on ARCH_S3C24XX for boards

Board options are already under "if ARCH_S3C24XX" condition, so
additional dependencies on this symbol can be removed.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>