drivers: OLPC: update various drivers to include olpc-ec.h

Switch over to using olpc-ec.h in multiple steps, so as not to break builds.
This covers every driver that calls olpc_ec_cmd().

Signed-off-by: Andres Salomon <dilinger@queued.net>
Acked-by: Paul Fox <pgf@laptop.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>