witherspoon: Add fan speed inc/dec control based on dimm temps

Created an event to increase or decrease fan speeds based on dimm
temperature, which includes having a precondition of both OCCs being
active, similar to the core temps.

Change-Id: Ia1bf52d566aa6370644f6bf68da928b51c2a6eba
Signed-off-by: Matthew Barth <msbarth@us.ibm.com>
1 file changed