[SCSI] libfc: add local port hook for provider session lookup

The target provider needs a per-instance lookup table
or other way to lookup sessions quickly without going through
a linear list or serializing too much.

Add a simple void * array indexed by FC-4 type to the fc_lport.

Signed-off-by: Joe Eykholt <jeykholt@cisco.com>
Committed-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

include/scsi/libfc.h

@@ -805,6 +805,7 @@ struct fc_disc {
  * @lp_mutex:              Mutex to protect the local port
  * @list:                  Handle for list of local ports
  * @retry_work:            Handle to local port for delayed retry context
+ * @prov:		   Pointers available for use by passive FC-4 providers
  */
 struct fc_lport {
 	/* Associations */
@@ -860,6 +861,7 @@ struct fc_lport {
 	struct mutex                   lp_mutex;
 	struct list_head               list;
 	struct delayed_work	       retry_work;
+	void			       *prov[FC_FC4_PROV_SIZE];
 };
 
 /**