ARM: EXYNOS: Remove unused DMC and CMU offsets and their mappings

Currently there is no user of DMC and CMU SFR offsets so we can safely
remove mapping of their SFR address space and cleanup related offset
macros from mach-exynos.

Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>