scsi: ufs: Introduce phy_initialization helper

Introduce phy_initialization helper since this is the only one variant
function without helper.

Link: https://lore.kernel.org/r/20201205120041.26869-3-stanley.chu@mediatek.com


Reviewed-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>