Merge changes I4ac6f9ef,I96bc377c,Ia5fdfb02,I601d24ef into msm-3.0

* changes:
  mmc: core: use non-reentrant workqueue for clock gating
  mmc: core: prevent aggressive clock gating racing with ios updates
  mmc: rename mmc_host_clk_{ungate|gate} to mmc_host_clk_{hold|release}
  Revert "mmc: fix a race between card-detect rescan and clock-gate work instances"