switchdev: add swdev ops

As discussed at netconf, introduce swdev_ops as first step to move switchdev
ops from ndo to swdev.  This will keep switchdev from cluttering up ndo ops
space.

Signed-off-by: Scott Feldman <sfeldma@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --cc include/linux/netdevice.h
Simple merge

diff --cc include/net/switchdev.h
Simple merge