Input: add driver for OpenCores Keyboard Controller

Driver for the keyboard hardware documented here:
	http://www.opencores.org/project,keyboardcontroller



Signed-off-by: Javier Herrero <jherrero@hvsistemas.es>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>