vxge: serialize access to steering control register

It is possible for multiple callers to access the firmware interface for
the same vpath simultaneously, resulting in uncertain output.  Add locks
to serialize access.  Also, make functions only accessed locally static,
thus requiring some movement of code blocks.
Signed-off-by: NJon Mason <jon.mason@exar.com>
Signed-off-by: NRam Vepa <ram.vepa@exar.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/vxge/vxge-config.h

@@ -641,6 +641,7 @@ struct __vxge_hw_virtualpath {
 	struct vxge_hw_vpath_stats_hw_info	*hw_stats;
 	struct vxge_hw_vpath_stats_hw_info	*hw_stats_sav;
 	struct vxge_hw_vpath_stats_sw_info	*sw_stats;
+	spinlock_t lock;
 };
 
 /*