Use audio_format_t consistently

Was sometimes int or uint32_t

Change-Id: Ib3d82f5aefeda371c0439e43e72737a54882f519
diff --git a/modules/audio/audio_policy.c b/modules/audio/audio_policy.c
index 409f0a1..e7d986a 100644
--- a/modules/audio/audio_policy.c
+++ b/modules/audio/audio_policy.c
@@ -96,7 +96,7 @@
 static audio_io_handle_t ap_get_output(struct audio_policy *pol,
                                        audio_stream_type_t stream,
                                        uint32_t sampling_rate,
-                                       uint32_t format,
+                                       audio_format_t format,
                                        uint32_t channels,
                                        audio_policy_output_flags_t flags)
 {
@@ -122,7 +122,7 @@
 
 static audio_io_handle_t ap_get_input(struct audio_policy *pol, int inputSource,
                                       uint32_t sampling_rate,
-                                      uint32_t format,
+                                      audio_format_t format,
                                       uint32_t channels,
                                       audio_in_acoustics_t acoustics)
 {