expanding on ethernet

expanded ethernet mac/phy, more configurability. replaced ethernet.o by the ethernet/ mac/phy files in f1/Makefile.
These should all be eth_mac_enable_xxx/eth_mac_disable_xxx form.  It makes it easier to find the thing you're looking for when you don't remember the feature bits acronyms, and it's more inline with how all the other peripherals are labelled.  (grep -r _enable_ will show you others)