Merge branch 'Implement-get_link_ksettings-for-VXLAN-and-bridge'

Matthias Schiffer says:

====================
Implement get_link_ksettings for VXLAN and bridge

Mesh routing protocol batman-adv (in particular the new BATMAN_V algorithm)
uses the link speed reported by get_link_ksettings to determine a path
metric for wired links. In the mesh framework Gluon [1], we layer VXLAN
and sometimes bridge interfaces on our Ethernet links.

These patches implement get_link_ksettings for these two interface types.
While this is obviously not accurate for bridges with multiple active
ports, it's much better than having no estimate at all (and in the
particular setup of Gluon, bridges with a single port aren't completely
uncommon).

[1] https://github.com/freifunk-gluon/gluon
====================

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