Merge branch 'ipvlan-deps'

Matteo Croce says:

====================
Remove IPVlan module dependencies on IPv6 and L3 Master dev

The IPVlan module currently depends on IPv6 and L3 Master dev.
Refactor the code to allow building IPVlan module regardless of the value
of CONFIG_IPV6 as done in other drivers like VxLAN or GENEVE.
Also change the CONFIG_NET_L3_MASTER_DEV dependency into a select,
since compiling L3 Master device alone has little sense.

$ grep -wE 'CONFIG_(IPV6|IPVLAN)' .config
CONFIG_IPV6=y
CONFIG_IPVLAN=m
$ ll drivers/net/ipvlan/ipvlan.ko
48K drivers/net/ipvlan/ipvlan.ko

$ grep -wE 'CONFIG_(IPV6|IPVLAN)' .config
CONFIG_IPVLAN=m
$ ll drivers/net/ipvlan/ipvlan.ko
44K drivers/net/ipvlan/ipvlan.ko
====================

Signed-off-by: David S. Miller <davem@davemloft.net>