ibmvnic: Split counters for scrq/pools/napi

The approach of one counter to rule them all when tracking the number
of active sub-crqs, pools, and napi has problems handling some failover
scenarios. This is due to the split in initializing the sub crqs,
pools and napi in different places and the placement of updating
the active counts.

This patch simplifies this by having a counter for tx and rx
sub-crqs, pools, and napi.

Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>