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/smsc/Kconfig b/drivers/net/ethernet/smsc/Kconfig
index f961928..1854c88 100644
--- a/drivers/net/ethernet/smsc/Kconfig
+++ b/drivers/net/ethernet/smsc/Kconfig
@@ -37,6 +37,7 @@
 config SMC91X
 	tristate "SMC 91C9x/91C1xxx support"
 	select CRC32
+	select NET_CORE
 	select MII
 	depends on (ARM || M32R || SUPERH || MIPS || BLACKFIN || \
 		    MN10300 || COLDFIRE)
@@ -56,6 +57,7 @@
 	tristate "SMC 91Cxx PCMCIA support"
 	depends on PCMCIA
 	select CRC32
+	select NET_CORE
 	select MII
 	---help---
 	  Say Y here if you intend to attach an SMC 91Cxx compatible PCMCIA
@@ -68,6 +70,7 @@
 	tristate "SMC EtherPower II"
 	depends on PCI
 	select CRC32
+	select NET_CORE
 	select MII
 	---help---
 	  This driver is for the SMC EtherPower II 9432 PCI Ethernet NIC,
@@ -78,6 +81,7 @@
 config SMC911X
 	tristate "SMSC LAN911[5678] support"
 	select CRC32
+	select NET_CORE
 	select MII
 	depends on (ARM || SUPERH || MN10300)
 	---help---
@@ -95,6 +99,7 @@
 	tristate "SMSC LAN911x/LAN921x families embedded ethernet support"
 	depends on (ARM || SUPERH || BLACKFIN || MIPS || MN10300)
 	select CRC32
+	select NET_CORE
 	select MII
 	select PHYLIB
 	---help---