nfp: tls: make use of kernel-driven TX resync

When TCP stream gets out of sync (driver stops receiving skbs
with expected TCP sequence numbers) request a TX resync from
the kernel.

We try to distinguish retransmissions from missed transmissions
by comparing the sequence number to expected - if it's further
than the expected one - we probably missed packets.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>