scsi: ufs: Remove unused UFS_BIT() macro

Since we have converted all the user of UFS_BIT() macro with the actual
bit position, let remove unused UFS_BIT()macro.

Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com>
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>