cmhw: Add stubs for SRE support

 * Add support for Sunlight Readability Enhancement, aka Facemelt Mode.
 * Optional dependency on adaptive backlight support, which is required
   in all current implementations.

Change-Id: Id25bb5fd384f3935383a5c7f5795ce17afc73b00
Hardware: Add high touch sensitivity support

Change-Id: Ia5ad3695ca253269dfe3a62420819ad9e9367f9c