scsi: ufs: ufshpb: Cache HPB Control mode on init

We will use control_mode later when we need to differentiate between device
and host control modes.

Link: https://lore.kernel.org/r/20210712095039.8093-2-avri.altman@wdc.com


Reviewed-by: Daejun Park <daejun7.park@samsung.com>
Signed-off-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>