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

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

On some platforms, host's M-PHY RX_FOM Attribute always reads 0, meaning SW
cannot rely on Figure of Merit (FOM) to identify the optimal TX
Equalization settings for device's TX Lanes. Implement the vops
ufs_qcom_get_rx_fom() such that SW can utilize the UFS Eye Opening Monitor
(EOM) to evaluate the TX Equalization settings for device's TX Lanes.

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/20260325152154.1604082-11-can.guo@oss.qualcomm.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>