witherspoon - Request speed based on tach feedback

Use the highest tach feedback from all the rotor feedbacks to base the
increase and decrease requested speed changes on.

Resolves openbmc/openbmc#2305

Change-Id: Ia1a71e53def045b021c3c798da3e8b07ae0a7c89
Signed-off-by: Matthew Barth <msbarth@us.ibm.com>
1 file changed