hal: Add support for Native Audio(44.1kHz)

- Changes for device/Usecase selection
- Add new and combo devices for headphones
- Combo device handling
- Add new backend and logic to handle multiple
  backends
- Remove hardcoded mixers and select them
  dynamically based on the device

Change-Id: I7207291f2c27da13ba0cc77c66de1144f4b9888a
diff --git a/hal/platform_api.h b/hal/platform_api.h
index 4ecdd36..0ae35e6 100644
--- a/hal/platform_api.h
+++ b/hal/platform_api.h
@@ -57,7 +57,7 @@
 int platform_set_mic_mute(void *platform, bool state);
 int platform_get_sample_rate(void *platform, uint32_t *rate);
 int platform_set_device_mute(void *platform, bool state, char *dir);
-snd_device_t platform_get_output_snd_device(void *platform, audio_devices_t devices);
+snd_device_t platform_get_output_snd_device(void *platform, struct stream_out *out);
 snd_device_t platform_get_input_snd_device(void *platform, audio_devices_t out_device);
 int platform_set_hdmi_channels(void *platform, int channel_count);
 int platform_edid_get_max_channels(void *platform);