st-hal: Migrate sound trigger hal to opensource location

Copy sound trigger hal code from proprietary location to
opensource. This is a snapshot of
AU_LINUX_ANDROID_LA.UM.8.12.08.00.00.484.157.

Additionally following changes are done for compilation and
opensource approval:
 - Removed outdated LICENSE file.
 - Updated NOTICE file.
 - Makefile path and enablement flag changes.
 - Update all copyright headers.

Change-Id: Ifeeae1c77016eb7512d1a8b1b61ebcf6d5f0cb5a
35 files changed