[SCSI] fcoe: Add support for FDMI in fcoe

This adds support for updating the FC-GS FDMI attributes
in the fcoe driver.

Signed-off-by: Neerav Parikh <neerav.parikh@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Acked-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>