Clean up USE_NEON to make it easier to disable NEON for benchmarking

Bug: 27242871
Change-Id: I30ba8bfe55885cde531706c760ec27e593d7f8b3
diff --git a/services/audioflinger/AudioResamplerFirOps.h b/services/audioflinger/AudioResamplerFirOps.h
index 658285d..2a26496 100644
--- a/services/audioflinger/AudioResamplerFirOps.h
+++ b/services/audioflinger/AudioResamplerFirOps.h
@@ -26,11 +26,15 @@
 #endif
 
 #if defined(__aarch64__) || defined(__ARM_NEON__)
+#ifndef USE_NEON
 #define USE_NEON (true)
-#include <arm_neon.h>
+#endif
 #else
 #define USE_NEON (false)
 #endif
+#if USE_NEON
+#include <arm_neon.h>
+#endif
 
 template<typename T, typename U>
 struct is_same