[build] Autogenerate DROID_DEVICE_FOO for droid device.
[util] Refactor HAL includes to per-droid-version headers.
[util] Define QCOM_HARDWARE for Hammerhead (Nexus 5).
[source] Use AUDIO_IN_VOICE_CALL_MONO only with QC hardware.
[util] Remove static from headers.
[util] Define QCOM_HARDWARE for Sbj (Jolla).