This patch adds bsg support to the iscsi class. There is only
1 request, the host vendor one, supported. It is expected that
this would be used for things like flash updates.

This patch is made over this one
http://marc.info/?l=linux-scsi&m=131149780020992&w=2Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>