[beta] touchscreen: add doubletap2wake for codina

this is a very simple and probably broken implementation of doubletap2wake. it senses for a touch and if two touches are not more than 500ms apart, the screen turns on. needs more extensive testing

Change-Id: Id177ef7c472a68e6d03a6f3eb65f693adbb17a4d
touchscreen: allow press timeout to be tunable

also changed all sweep2wake vars to unsigned just in case

Change-Id: I5fe6e334f8c1498148e7e0188c2de8655ec7b0c2