action.c must desist in calling set_cpu_frequency from a tick

The function is neither reentrant nor ISR callable. Instead of
using a ticked-based timeout, have the button driver provide the
unboost after a delay when waiting for a button.

HAVE_GUI_BOOST gets immediate boost after dequeuing any message,
otherwise the queue has to have at least three messages waiting
for it to trigger a boost-- essentially the behavior that existed
but now combined in one place.

Change-Id: I1d924702840f56a1a65abe41fa92b4e753c4e75a
3 files changed