sfc: Use generic MDIO functions and definitions

Make use of the newly-added generic MDIO clause 45 support and remove
redundant definitions.

Add an 'efx_' prefix to the remaining driver-specific MDIO functions
and remove arguments which are redundant with efx->mdio.prtad.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/sfc/selftest.h b/drivers/net/sfc/selftest.h
index 39451cf..f6feee0 100644
--- a/drivers/net/sfc/selftest.h
+++ b/drivers/net/sfc/selftest.h
@@ -32,7 +32,7 @@
  */
 struct efx_self_tests {
 	/* online tests */
-	int mii;
+	int mdio;
 	int nvram;
 	int interrupt;
 	int eventq_dma[EFX_MAX_CHANNELS];