Lan91c111 daughtercard support for NiosII

I did get the posted driver code to work for me with some changes.

My hw had some problems initially, so you may just want to try the code as is.

I believe for the posted code, you will need to connect A1,A2,A3 and SBE0,SBE1. The registers will be on 16bit boundaries.

If you want to go the route I went, do the following:

My interest was in a minimal pin count interface (24pins). You could also save another 8pins using an 8bit bus.

I followed the CPU32 connection scheme for 16bit bus using A2,A3,A4 and SBE1#. This places all registers on full word boundaries.

I changed the class.ptf to use native rather than dynamic address alignment.

I modified the ..regs.h file to support the above changes.

There were a few fixes needed in the alignment code of the low level data transfer functions, and the mac address/ip address code.

For simplicity, turn off dhcp in LWIP and use a static IP to test with.