Remove dependencies on hardware/audio_policy.h

Most of the time it's not needed, may be needed when
USE_LEGACY_AUDIO_POLICY is enabled.

Test: make

Change-Id: Id25eafc05352f07614965913d367d484f2673fbd
diff --git a/services/audiopolicy/service/AudioPolicyService.cpp b/services/audiopolicy/service/AudioPolicyService.cpp
index ec39a79..b6b6116 100644
--- a/services/audiopolicy/service/AudioPolicyService.cpp
+++ b/services/audiopolicy/service/AudioPolicyService.cpp
@@ -36,10 +36,13 @@
 #include <media/AudioEffect.h>
 #include <media/AudioParameter.h>
 
-#include <hardware/hardware.h>
 #include <system/audio.h>
 #include <system/audio_policy.h>
+
+#ifdef USE_LEGACY_AUDIO_POLICY
+#include <hardware/hardware.h>
 #include <hardware/audio_policy.h>
+#endif
 
 namespace android {