Fixed hardware detection.

The previous chip detection was inspired by the old IP65 driver code. For some reason it didn't work as expected. The new code is simpler and based on this statement in the chip datasheet: "The upper byte always reads as 33h and can be used to help determine the I/O location of the LAN91C96."
Merge pull request #750 from oliverschmidt/master

Fixed hardware detection.
Add missing semi-colon
Merge pull request #753 from kartben/patch-1

Add missing semi-colon
Merge commit 'd7cf3b1f74159dead531d9a0da6fcd02ad6cdb5d' into HEAD