eth: fbnic: Collect packet statistics for XDP

eth: fbnic: Collect packet statistics for XDP

Add support for XDP statistics collection and reporting via rtnl_link
and netdev_queue API.

For XDP programs without frags support, fbnic requires MTU to be less
than the HDS threshold. If an over-sized frame is received, the frame
is dropped and recorded as rx_length_errors reported via ip stats to
highlight that this is an error.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Mohsin Bashir <mohsin.bashr@gmail.com>
Link: https://patch.msgid.link/20250813221319.3367670-9-mohsin.bashr@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>