PCem

This is a small incomplete patch that enables the CMOS Setup of the Intel Zappa to show the correct CPU speed. I'd like some input in the incomplete parts.

It detects CPU type by comparing strings - this should NOT be done, but I couldn't think fast of a better way to do it. I was going to compare CPU speed and multiplier, but PCem's multiplier is an integer (and these CPUS have non-integer multipliers).
It also doesn't support the Overdrive CPUs because I don't know how they should be configured in the motherboard!

Probably better to use the clockspeed in cpu_s->rspeed.

I initially ran away from that because of the integer speed multiplier (so I couldn't disambiguate from 100/50 and 100/66), but I just used the PCI speed for that.

It's also curious that the keyboard detection fails at 120 and 133 MHz. I didn't look into that.

Committed at rev 1526. I also ported it to Advanced/EV (not that the BIOS for that board shows the CPU speed!), and fixed the keyboard detection above 100 MHz.