scsi: ufs: remove code duplication from ufs specific phy

In this change, code that is duplicated in specific ufs msm PHYs
modules is removed, and helper functions that contain the common
code are added to ufs-msm-phy.c.

Change-Id: I30ca8b4d4b452450a155671da94f03d7b965160a
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>