liquidio: Disabling tasklet when NAPI is active

Control packets are processed in tasklet when interface is down and in
NAPI when interface is up. So tasklet can be disabled when interface up
and re-enabled when interface is down.

Signed-off-by: Intiyaz Basha <intiyaz.basha@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>