ARM: SAMSUNG: Remove unused register offset definition

This patch cleans up various map.h under mach-exynos, mach-s3c24xx and
plat-samsung by removing unused register offset. This patch also does a
minor nitpick of changing EXYNOS4 to EXYNOS from comment section of
header file "mach-exynos/include/mach/map.h".

Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>