scsi: ufs: qcom: Add phy_exit call in hcd exit path

Do a phy_exit() over the ufs phy in the ufs qcom exit path
to de-initialize the phy.

Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
Reviewed-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>