net: Move MII out from under NET_CORE and hide it

All drivers that select MII also need to select NET_CORE because MII
depends on it.  This is a bit ridiculous because NET_CORE is just a
menu option that doesn't enable any code by itself.

There is also no need for it to be a visible option, since its users
all select it.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/Kconfig

@@ -25,6 +25,9 @@ menuconfig NETDEVICES
 # that for each of the symbols.
 if NETDEVICES
 
+config MII
+	tristate
+
 config NET_CORE
 	default y
 	bool "Network core driver support"
@@ -100,13 +103,6 @@ config NET_FC
 	  adaptor below. You also should have said Y to "SCSI support" and
 	  "SCSI generic support".
 
-config MII
-	tristate "Generic Media Independent Interface device support"
-	help
-	  Most ethernet controllers have MII transceiver either as an external
-	  or internal device.  It is safe to say Y or M here even if your
-	  ethernet card lacks MII.
-
 config IFB
 	tristate "Intermediate Functional Block support"
 	depends on NET_CLS_ACT