scsi: ufs: program number of TX lanes to drive in MSM UFS PHY

After link startup the phy adapter (PA) layer in Uni-Pro
automatically detects the number of available lanes for
communication with the device. Since it is choice of s/w
to use all the available lanes or a partial of them, it is
necessary to communicate to MSM PHY about the lanes not being
used so that PHY can stop driving them.

Change-Id: I6f005e67a4c0a35dcba0ff186de5817af1b0439d
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>