Input: imx_keypad - make sure keyboard can always wake up system

Input: imx_keypad - make sure keyboard can always wake up system

There are several scenarios that keyboard can NOT wake up system
from suspend, e.g., if a keyboard is depressed between system
device suspend phase and device noirq suspend phase, the keyboard
ISR will be called and both keyboard depress and release interrupts
will be disabled, then keyboard will no longer be able to wake up
system. Another scenario would be, if a keyboard is kept depressed,
and then system goes into suspend, the expected behavior would be
when keyboard is released, system will be waked up, but current
implementation can NOT achieve that, because both depress and release
interrupts are disabled in ISR, and the event check is still in
progress.

To fix these issues, need to make sure keyboard's depress or release
interrupt is enabled after noirq device suspend phase, this patch
moves the suspend/resume callback to noirq suspend/resume phase, and
enable the corresponding interrupt according to current keyboard status.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>