BUSDMA for en(4)

This has been commited to -CURRENT

en1.diff patch to busdma-ify the driver for Efficient networks and Adaptec ATM cards.

This patch is rather large because I had to re-arrange the code for busdma. While doing this I also decided to bring it to KNF. It does the following things:

The driver has been tested with ENI client and server cards and an Adaptec card (thanks to Kenjiro for this card) on both i386 and sparc64. Performance is as expected: TCP througput between a Sparc Ultra 10 and an 900MHz i386 is around 8 and 14MBit/s depending on the direction.

Old versions of the patch: