input: Introduce State Notifier (adapted for markw)

This driver is used to help another drivers handle different tasks
for different device's states (active/suspended). It gets the current
state from reliable source (MDSS Panel in this case) and exports it
to kernel space.

This can become a reliable generic replacement for LCD Notify.

Change-Id: Ie41a96e201dff8e80bbb7d4f98f01a1c2131f565
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
Signed-off-by: Alex Saiko <solcmdr@gmail.com>