cpuidle: governor: menu: don't use loadavg

get_loadavg doesn't work as intended.  According to the comments, it
should be returning an average over a few seconds, but it is actually
reading the instantaneous load.  It is almost always returning 0, but
can sometimes, depending on workload, spike very high into the hundreds
even when the average cpu load is under 10%.  Disable it for now.

Change-Id: I63ed100af1cf9463549939b8113ed83676db5f86
Signed-off-by: Colin Cross <ccross@android.com>