scsi: ufs-msm: change default working mode to rate B

Working throughput in UFS is affected by Gear, Number of lanes, and Mode
(PWM: Slow / SlowAuto,
 or
 HS: Fast /FastAuto).
When working in HS, throughput is affected by additional parameter -
Rate (A / B).
Here, we change the default working rate in HS to Rate B.

Change-Id: I35f63d5fc90ad1be19d886dda0bdcd4e54fe9c4c
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>