[infiniband] Allow drivers to override the eIPoIB LEMAC

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/drivers/net/ipoib.c

 	/* Extract hardware address */
 	memcpy ( netdev->hw_addr, &ibdev->gid.s.guid,
 		 sizeof ( ibdev->gid.s.guid ) );
+	memcpy ( netdev->ll_addr, ibdev->lemac, ETH_ALEN );
 
 	/* Set local MAC address */
 	memcpy ( &ipoib->mac.gid.s.guid, &ibdev->gid.s.guid,

src/include/ipxe/infiniband.h

 #include <ipxe/tables.h>
 #include <ipxe/ib_packet.h>
 #include <ipxe/ib_mad.h>
+#include <ipxe/if_ether.h>
 
 /** Subnet management interface QPN */
 #define IB_QPN_SMI 0
 	/** General services interface */
 	struct ib_mad_interface *gsi;
 
+	/** IPoIB LEMAC (if non-default) */
+	uint8_t lemac[ETH_ALEN];
+
 	/** Driver private data */
 	void *drv_priv;
 };