if_bnxt: Implementation of Extended Port Hardware Stats Support for THOR Controller

[chandrakanth.patil_broadcom.com]

Summary

The newly added port extended hardware statistics are now accessible to
users through the sysctl interface. Also, Few obsolete stats are removed
and few stats are renamed.

[imp]

This was was tricky.. I think all this is good, but I can't be sure w/o access to thor data.
I didn't see anything obviously wrong, but there may be some contexts that things are called in that are wrong.
I can't check because of the limited context diff used. Eyeballing from the in-tree driver suggests that it's fine.
Please either use git arc to update lhe patches, or generate the raw diffs with -U99999 so that we have the full context in this tool.