[NET_SCHED]: sch_ingress: remove unnecessary ops

- ->reset is optional
- sch_api provides identical defaults for ->dequeue/->requeue
- ->drop can't happen since ingress never has a parent qdisc

Signed-off-by: Patrick McHardy <kaber@trash.net>
Acked-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>