Samsung mach/soc changes for v5.2

1. Cleanup in mach code.
2. Add necessary fixes for Suspend to RAM on Exynos5422 boards (tested
   with Odroid XU3/XU4/HC1 family).  Finally this brings a working S2R
   on these Odroid boards (still other drivers might have some issues
   but mach code seems to be finished).
3. Require MCPM for Exynos542x boards because otherwise not all of cores
   will come online.
4. GPIO regulator cleanup on S3C6410 Craig.