Hook the MFP code into the power management code so that the MFPs can
be reconfigured when suspending and resuming.  However, note the FIXME
- low power mode MFP configuration may depend on the system state being
entered.

Also note that we have to clear any detected edge events prior to
entering a low power mode - otherwise we immediately wake up.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>