scsi: ufs: ufs-qcom: Add support for finding max gear on new platforms

Starting from Qcom UFS version 4.0, vendor specific REG_UFS_PARAM0 register
can be used to determine the maximum gear supported by the controller.

Suggested-by: Can Guo <quic_cang@quicinc.com>
Reviewed-by: Andrew Halaney <ahalaney@redhat.com>
Tested-by: Andrew Halaney <ahalaney@redhat.com> # Qdrive3/sa8540p-ride
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>