qede: Refactor statistics gathering

qede: Refactor statistics gathering

Orabug: 25477939

Refactor logic for gathering statistics into a per-queue function.
This improves readability of the driver statistics' flows.

In addition, this would be required by the XDP forwarding queues
[as we'll need the Txq statistics gathering methods for those as well].

Signed-off-by: Yuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 4dbcd6400244a073f579665a957c6c56c99cc3b6)
Signed-off-by: Brian Maly <brian.maly@oracle.com>