[SCSI] iscsi class: add bsg support to iscsi class

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=2

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
index 8d9dae8..4a79b9d 100644
--- a/drivers/scsi/Kconfig
+++ b/drivers/scsi/Kconfig
@@ -309,6 +309,7 @@
 config SCSI_ISCSI_ATTRS
 	tristate "iSCSI Transport Attributes"
 	depends on SCSI && NET
+	select BLK_DEV_BSGLIB
 	help
 	  If you wish to export transport-specific information about
 	  each attached iSCSI device to sysfs, say Y.