ARM: EXYNOS4: Add EXYNOS4 CPU initialization support

This patch adds EXYNOS4 CPU support files in mach-exynos4,
and basically they are moved from mach-s5pv310 so that it
can support Samsung's new CPU name, EXYNOS4.
The EXYNOS4 ingegrates a ARM Cortex A9 multi-core.

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