hal: Fix bit width for 24 bit PCM offload playback

PCM offload bit width is selected as 16 bit even for 24 bit pcm offload
playback streams if QTI_FLAC_DECODER flag is not defined. Fix this issue
by defining appropriate flag PCM_OFFLOAD_ENABLED_24.

Change-Id: I82169252770b764344bf4531fb994e2195244dde
diff --git a/hal/Android.mk b/hal/Android.mk
index 9d78ddc..38873cf 100644
--- a/hal/Android.mk
+++ b/hal/Android.mk
@@ -160,6 +160,10 @@
     LOCAL_CFLAGS += -DQTI_FLAC_DECODER
 endif
 
+ifeq ($(strip $(AUDIO_FEATURE_ENABLED_PCM_OFFLOAD_24)),true)
+       LOCAL_CFLAGS += -DPCM_OFFLOAD_ENABLED_24
+endif
+
 ifeq ($(strip $(AUDIO_FEATURE_ENABLED_DEV_ARBI)),true)
     LOCAL_CFLAGS += -DDEV_ARBI_ENABLED
     LOCAL_SRC_FILES += audio_extn/dev_arbi.c