[lm-sensors] FAQ update

[Jean Delvare]

Hi all,

Ticket #2068 suggested that we add a FAQ entry about our position
towards undocumented chips. I thought it was a good idea, and did that.
This is FAQ 5.9. As this is supposed to reflect a relatively collective
position, active contributors are invited to comment and reword if
needed.

I also dropped FAQ 6.9, which was related to the old mailing list and
doesn't apply to the new one.

BTW, any objection to me dropping the whole section dedicated to
lm_sensors 1? Looks like noise to me now.

Thanks,
-- 
Jean Delvare