ARM: S5PV310: update S5PV310 Kconfig for supporting multiple machines

This patch updates Kconfig of mach-s5pv310 for easily dividing S5PC210
and S5PV310 boards. S5PC210(MCP) machines and S5PV310 machines can be
build into one kernel, this will be provied/submitted when new defconfig
can be merged.

Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>