sfc: Implement ethtool reset operation

Refactor efx_reset_down() and efx_reset_up() accordingly.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/sfc/efx.h b/drivers/net/sfc/efx.h
index c785003..fa40c7b 100644
--- a/drivers/net/sfc/efx.h
+++ b/drivers/net/sfc/efx.h
@@ -71,6 +71,7 @@
 extern const struct ethtool_ops efx_ethtool_ops;
 
 /* Reset handling */
+extern int efx_reset(struct efx_nic *efx, enum reset_type method);
 extern void efx_reset_down(struct efx_nic *efx, enum reset_type method);
 extern int efx_reset_up(struct efx_nic *efx, enum reset_type method, bool ok);