hal: configure playback stream rendering based on output policy

For the usecases where individual streams have to be rendered
through different post processing chain on DSP an output policy
is defined. The output configuration is read from the
output policy file based on the stream atrributes to render the
playback appropriately.

Change-Id: I095592013ffa5b04bea69254026ebb78e2934822
diff --git a/hal/platform_api.h b/hal/platform_api.h
index bf6bdcb..15deea5 100644
--- a/hal/platform_api.h
+++ b/hal/platform_api.h
@@ -31,6 +31,7 @@
 int platform_set_fluence_type(void *platform, char *value);
 int platform_get_fluence_type(void *platform, char *value, uint32_t len);
 int platform_set_snd_device_acdb_id(snd_device_t snd_device, unsigned int acdb_id);
+int platform_get_snd_device_acdb_id(snd_device_t snd_device);
 int platform_send_audio_calibration(void *platform, snd_device_t snd_device);
 int platform_switch_voice_call_device_pre(void *platform);
 int platform_switch_voice_call_enable_device_config(void *platform,