ena: Improve reset reason statistics

[osamaabb_amazon.com]

Summary

The driver uses different reset reasons.
Some of them are counted and presented in the driver statistics.
There are cases where statistics are counted on a ring level,
but these are zeroed after a reset procedure takes place.

This commit makes the following changes:

1. Add statistics for the unrepresented reset reasons.
2. Add reset reasons which are counted on a ring level,

to be also global for better tracking.

Approved by: cperciva
MFC after: 2 weeks
Sponsored by: Amazon, Inc.