S2IO: Added a loadable parameter to enable or disable vlan stripping in frame.

- Added code to not to strip vlan tag when driver is in promiscuous mode
- Added module loadable parameter 'vlan_tag_strip" through which user can
  enable or disable vlan stripping irrespective of mode
  ( promiscuous or non-promiscuous ).

Signed-off-by: Sivakumar Subramani <sivakumar.subramani@neterion.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/net/s2io.h b/drivers/net/s2io.h
index d23a50f..803137c 100644
--- a/drivers/net/s2io.h
+++ b/drivers/net/s2io.h
@@ -297,6 +297,9 @@
 	struct xpakStat xpak_stat;
 };
 
+/* Default value for 'vlan_strip_tag' configuration parameter */
+#define NO_STRIP_IN_PROMISC 2
+
 /*
  * Structures representing different init time configuration
  * parameters of the NIC.