Input: omap4-keypad - wake-up on events & long presses

Program keyboard controller to generate a wake-up request on events and
on long key presses. It will not generate wake-up requests on timeouts
since driver code does not handle them.

This allows keyboard to wake-up OMAP from suspend.

Signed-off-by: Mike Turquette <mturquette@ti.com>
Signed-off-by: Abraham Arce <x0066660@ti.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>