[SCSI] be2iscsi: Add support for configuring the VLAN on the adapter.

Add support for configuring the VLAN parameters on the adapter
using the iscsiadm interface.

Signed-off-by: John Soni Jose <sony.john-n@emulex.com>
Signed-off-by: Jayamohan Kallickal <jayamohan.kallickal@emulex.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>