hal: Port the dock support to non-legacy 8960 hal

- allows to define and use 'dock' and 'speaker-and-dock' mixer paths
- can be enabled by the same board flags used in legacy hal:
  BOARD_USES_MOTOROLA_EMU_AUDIO or BOARD_HAVE_SAMSUNG_AUDIO

Change-Id: I04732856ee2b87295aced3e01995720009900974