net: thunderx: Reset RXQ HW stats when interface is brought down

When SQ/TXQ is reclaimed i.e reset it's stats also automatically reset
by HW. This is not the case with RQ. Also VF doesn't have write access
to statistics counter registers. Hence a new Mbox msg is introduced which
supports resetting RQ, SQ and full Qset stats. Currently only RQ stats
are being reset using this mbox message.

Signed-off-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
Signed-off-by: Sunil Goutham <sgoutham@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>