Merge branch 'thunderx-xdp-mtu'

Matteo Croce says:

====================
Fix thunderx MTU with XDP

The thunderx driver can't use XDP with all MTU values.
This patches sets the right MTU values, and add a check to avoid setting
a wrong value which will not function.

v3: Fix a copy-paste from two functions, tested on proper hardware:

2: enP2p1s0v0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP mode DEFAULT group default qlen 1000
    link/ether 1c:1b:0d:0d:52:a4 brd ff:ff:ff:ff:ff:ff
[  787.019730] nicvf 0002:01:00.1 enP2p1s0v0: Jumbo frames not yet supported with XDP, current MTU 1800.
RTNETLINK answers: Operation not supported
[  800.574568] nicvf 0002:01:00.1 enP2p1s0v0: Link is Up 10000 Mbps Full duplex
[  807.248321] nicvf 0002:01:00.1 enP2p1s0v0: Jumbo frames not yet supported with XDP, current MTU 1500.
RTNETLINK answers: Invalid argument
====================

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