hog: Add initial files for suspend support

hog: Add initial files for suspend support

This patch adds the initial files to support HoG suspend. The suspend
concept for HoG is implementation specific. The proposal is allowing
back-end selection at build time. Each Linux distribution/platform is
responsible for defining and writting their own policy to manage suspend
on HoG capable devices.

When setting the Control Point, the report device can execute actions to
save power. eg: Reduce the cycle of the key press detection or disable
LEDs.