MFC r266270:
Remove some unused variables.
MFC r266490, r266738, r267955, and r268209:
- Improve performance by fixing incorrect Rx/Tx handling
- Rename definition of AXGE_* to reflect reality
- Add new USB IDs
- Add proper rangechecks in "axge_rx_frame()" function and
fix receive loop header parsing.
- Disable hardware checksumming until it is properly tested.

PR:	191432