scsi: ufs: ufs-mediatek: Correct operator & -> &&

The "lpm" and "->enabled" are all boolean. We should be using &&
rather than the bit operator.

Link: https://lore.kernel.org/r/1615896915-148864-1-git-send-email-dj0227@163.com
Fixes: 488edafb

 ("scsi: ufs-mediatek: Introduce low-power mode for device power supply")
Reviewed-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: dongjian <dongjian@yulong.com>
Signed-off-by: Yue Hu <huyue2@yulong.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>