tg3: Add mdio bus registration

This patch introduces code to register and unregister the tg3 mdio bus
with the system.

Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: Benjamin Li <benli@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index 9f6cc8a..78cc949 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -2228,6 +2228,7 @@
 config TIGON3
 	tristate "Broadcom Tigon3 support"
 	depends on PCI
+	select PHYLIB
 	help
 	  This driver supports Broadcom Tigon3 based gigabit Ethernet cards.