liquidio: Swap VF representor Tx and Rx statistics

Swap VF representor tx and rx interface statistics since it is a
virtual switchdev port and tx for VM should be rx for VF representor
and vice-versa.

Signed-off-by: Srinivas Jampala <srinivasa.jampala@cavium.com>
Acked-by: Derek Chickles <derek.chickles@cavium.com>
Signed-off-by: Felix Manlunas <felix.manlunas@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>