scsi: ufs: ufs-mediatek: Disable HCI before HW reset

MediaTek ufshci needs to be disabled before HW reset to avoid potential
issues.

Link: https://lore.kernel.org/r/20210528033624.12170-3-alice.chao@mediatek.com


Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Alice.Chao <alice.chao@mediatek.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>