Merge changes If9c6d64e,Ice2ac474,I38bcd9d6,I167d09c1 into msm-3.0

* changes:
  msm: bam_dmux: remove obsolete mutex
  msm: bam_dmux: change mutex to spinlock
  msm: bam_dmux: change kmalloc() while in atomic context to GFP_ATOMIC
  msm: bam_dmux: release read lock in error scenarios