audiohal: Modify platform info for msm8916

Assign the backend mixer control based on interface.
Add support to set channels for afe backend for playback.

Change-Id: Ia870cb51b9e76700ef67812ee9af1437c76bf18c
diff --git a/hal/Makefile.am b/hal/Makefile.am
index 3274195..9f5214a 100644
--- a/hal/Makefile.am
+++ b/hal/Makefile.am
@@ -153,5 +153,5 @@
 audio_primary_default_la_CFLAGS += -Dstrlcat=g_strlcat
 audio_primary_default_la_CFLAGS += -DINT_MAX=0x7fffffff
 audio_primary_default_la_CFLAGS += -D__unused=__attribute__\(\(__unused__\)\)
-audio_primary_default_la_CFLAGS += -DLINUX_ENABLED $(TARGET_CFLAGS)
+audio_primary_default_la_CFLAGS += -DLINUX_ENABLED $(TARGET_CFLAGS) -DAUDIO_EXTN_FORMATS_ENABLED
 audio_primary_default_la_LDFLAGS = -module -shared -avoid-version