speedstep-piix4 don't work

[Kenneth Ho <ken.ho@theorem.ca>]

The latest patch posted on this mailing list, against 2.4.21-ac4, 
doesn't work on my Thinkpad X20.

The CPU is a Speedstep capable P3@600MHz, whose clockspeed varies from 
260 to 600 depending on BIOS settings and AC power (as reported during 
testing with speedstep-detect and bootup). speedstep-detect also catches 
a single bit GPO change when switching from AC to battery on boot, with 
BIOS settings at automatic defaults.

GPOs changes from 0x767bbfe to 0x767fbbff after disconnecting the AC. 
This should be gpo_hilo=0.

Calling modprobe speedstep-piix4 gpo_hilo=0 leaves dmesg saying cpufreq: 
changed failed.

Using the old speedstep_bx module on poupinou with gpo_hilo=0 yields the 
following (success) output on dmesg:
gpo_hilo: 0x34
gpo_hilo_shift: 0x0
frequency_high: 600000
frequency_low: 500000

I'd like to use the autospeedstep daemon for neat powersaving-ness so 
any assistance and troubleshooting would be appreciated.

(Incidentally, the patch posted leaves out a dependency of 
speedstep-lib.o - so I added it to the arch/i386/kernel/Makefile)