scsi: ufs: ufs-qcom: Implement vops tx_eqtr_notify()

scsi: ufs: ufs-qcom: Implement vops tx_eqtr_notify()

On some platforms, HW does not support triggering TX EQTR from the most
reliable High-Speed (HS) Gear (HS Gear1), but only allows to trigger TX
EQTR for the target HS Gear from the same HS Gear. To work around the HW
limitation, implement vops tx_eqtr_notify() to change Power Mode to the
target TX EQTR HS Gear prior to TX EQTR procedure and change Power Mode
back to HS Gear1 (the most reliable gear) post TX EQTR procedure.

Reviewed-by: Bean Huo <beanhuo@micron.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Can Guo <can.guo@oss.qualcomm.com>
Reviewed-by: Peter Wang <peter.wang@mediatek.com>
Link: https://patch.msgid.link/20260325152154.1604082-10-can.guo@oss.qualcomm.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>