scsi: ufs-qcom: make RATE B-series as default in HS gear mode

RATE B-Series has 15% higher interface speed compared to Rate A-Series
hence it can help boost the sequential read performance. Make Rate
B-series as default one for performance reasons, for power savings we
already have clock gating/scaling and runtime PM mechanism which would
kick in whenever appropriate to save power.

Change-Id: Ifd23184fd623fa0ee7c277cf199c536e28d292ad
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>