MII: fix Kconfig dependencies for MII

MII Kconfig option is apart of the core networking drivers and
by default NET_CORE is enabled so drivers selecting MII will
have MII enabled as well.  It was found using the randconfig
option during testing, MII would be selected but NET_CORE
could be disabled.  This caused a dependency error.

Resolved the dependency by selecting NET_CORE when MII is
selected.

Reported-by: Emil Tantilov <emil.s.tantilov@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/atheros/Kconfig b/drivers/net/ethernet/atheros/Kconfig
index 26ab8ca..1ed886d 100644
--- a/drivers/net/ethernet/atheros/Kconfig
+++ b/drivers/net/ethernet/atheros/Kconfig
@@ -22,6 +22,7 @@
 	tristate "Atheros L2 Fast Ethernet support"
 	depends on PCI
 	select CRC32
+	select NET_CORE
 	select MII
 	---help---
 	  This driver supports the Atheros L2 fast ethernet adapter.
@@ -33,6 +34,7 @@
 	tristate "Atheros/Attansic L1 Gigabit Ethernet support"
 	depends on PCI
 	select CRC32
+	select NET_CORE
 	select MII
 	---help---
 	  This driver supports the Atheros/Attansic L1 gigabit ethernet
@@ -45,6 +47,7 @@
 	tristate "Atheros L1E Gigabit Ethernet support (EXPERIMENTAL)"
 	depends on PCI && EXPERIMENTAL
 	select CRC32
+	select NET_CORE
 	select MII
 	---help---
 	  This driver supports the Atheros L1E gigabit ethernet adapter.
@@ -56,6 +59,7 @@
 	tristate "Atheros L1C Gigabit Ethernet support (EXPERIMENTAL)"
 	depends on PCI && EXPERIMENTAL
 	select CRC32
+	select NET_CORE
 	select MII
 	---help---
 	  This driver supports the Atheros L1C gigabit ethernet adapter.