ANDROID: input: Generic GPIO Input devices

Supports keyboard matrixces, direct inputs, direct outputs and axes connected to gpios.

Change-Id: I5e921e6e3a1cc169316ee3b665f4cc21b5735114
Signed-off-by: Arve Hjønnevåg <arve@android.com>
Signed-off-by: Nick Pelly <npelly@google.com>

[AmitP: Use ktime directly to align with upstream commit
        2456e855 ("ktime: Get rid of the union")]
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>