ARM: 7248/1: S5PV210: introduce arch/arm/mach-s5pv210/common.[ch]

This patch introduces common.[ch] which are used only in the
arch/arm/mach-s5pv210/ directory. The common.c file merges
the cpu.c and init.c which are used commonly on S5PCV210/S5PC100
SoC and the common.h local header file replaces with plat/s5pv210.h
file.

Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>