[LinuxBIOS] sc520 support is in

[Ronald G Minnich]

you can now build an sc520 bios for the digital logic msm586sev, and the 
ethernet works. Due to a glitch with hardware, the name of the target is 
mem586seg; I plan to fix this problem. For now, it's a great little 
cluster node.

msm586sev is a nice little board, small, low power.

To-dos
- no vga bios yet (well, not totally, you can get it in user mode with
    the "testbios' program in linuxbios utilities, just not in linuxbios
    itself)
- need to finish up dynamic memory sizing code
- keyboard stuck error (no kb interrupts?)
- reset is still not reliable

this cpu was kind of a bear, and still does not fit well into the 
linuxbios way of doing things, and never will be that good a fit due to 
architectural design problems with the FLASH address map(see linux 
journal web article). I'm going to build a cluster of them anyway ...

ron