scsi: lpfc: Enable fw download on if_type=6 devices

Current code is very explicit in what it allows to be downloaded.
The driver checking prevented G7 firmware download. The driver
checking is unnecessary as the device will validate what it receives.

Revise the firmware download interface checking.
Added a little debug support in case there is still a failure.

Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <james.smart@broadcom.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>