hwspinlock/msm: Add snapshot of remote_spinlock driver

This is a snapshot of the msm remote_spinlock driver as of msm-4.4
commit <aaf356abef2> (Merge "scsi: ufs: add 2 lane support").

In addition, fix coding style issues and add comments to memory
barriers.

CRs-Fixed: 1059650
Change-Id: Ib907647e38fbd7c6bcdc724a92518959431da56e
Signed-off-by: Chris Lew <clew@codeaurora.org>