Moved the legacy noise suppressor to a separate build target

Bug: webrtc:5298
Change-Id: Ia1c5eb9d0f7b4ba578acb646e73229de63ae91fb
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/161441
Reviewed-by: Gustaf Ullberg <gustaf@webrtc.org>
Commit-Queue: Per Åhgren <peah@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#30089}
diff --git a/modules/audio_processing/audio_processing_impl.h b/modules/audio_processing/audio_processing_impl.h
index dcc2fa6..08379ad 100644
--- a/modules/audio_processing/audio_processing_impl.h
+++ b/modules/audio_processing/audio_processing_impl.h
@@ -27,7 +27,7 @@
 #include "modules/audio_processing/include/aec_dump.h"
 #include "modules/audio_processing/include/audio_processing.h"
 #include "modules/audio_processing/include/audio_processing_statistics.h"
-#include "modules/audio_processing/legacy_noise_suppression.h"
+#include "modules/audio_processing/legacy_ns/legacy_noise_suppression.h"
 #include "modules/audio_processing/level_estimator.h"
 #include "modules/audio_processing/ns/noise_suppressor.h"
 #include "modules/audio_processing/render_queue_item_verifier.h"