scsi: fdomain: use BCTL_RST in fdomain_reset()

Commit 1697c6a6 ("scsi: fdomain: Add register definitions") somehow
missed the use of BCTL_RST in fdomain_reset(), leaving the magic number
intact.  Fix this issue (with no change in the generated object file).

Fixes: 1697c6a6 ("scsi: fdomain: Add register definitions")
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>