Revert "msm: remove rq_stats and mp_decision"

This reverts commit 28085469cee4aeb7e85eae03e09712cbd3e31e24.
msm: re-remove mp_decision after revert
msm_rq_stats: added support enable load calculation on demand

Conflicts:
	arch/arm/mach-msm/msm_rq_stats.c