ARM: EXYNOS: Move PMU specific definitions from common.h

This patch moves PMU specific definitions into a new file
as exynos-pmu.h.
This will help in reducing dependency of common.h in pmu.c.

Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
Tested-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>