Merge branch 'l2tp-module-autoloading'

Stephen Hemminger says:

====================
l2tp: module autoloading

With L2TP it was necessary to manually load modules
which is a nuisance and not required with other tunneling
protocols. This set of patches adds the aliases and module
load hook to get rid of the necessity of modprobing.
====================

Acked-By: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>