ARM: SAMSUNG: Make legacy MFC support code depend on SAMSUNG_ATAGS

This allows to bypass compilation of static platform device and resource
definitions that require interrupts and base addresses to be defined
statically.

Cc: Jeongtae Park <jtp.park@samsung.com>
Cc: Kamil Debski <k.debski@samsung.com>
Signed-off-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>