liquidio: fix wrong info about vf rx/tx ring parameters reported to ethtool

Information reported to ethtool about vf rx/tx ring parameters is wrong.
Fix it by adding the missing initializations.

Signed-off-by: Intiyaz Basha <intiyaz.basha@cavium.com>
Signed-off-by: Felix Manlunas <felix.manlunas@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>