Move echo_control.h to api/audio

Bug: webrtc:8844
Change-Id: I5c2406c43ade786c26e12b3c847fed8424283df0
Reviewed-on: https://webrtc-review.googlesource.com/53700
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Commit-Queue: Gustaf Ullberg <gustaf@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#22031}
diff --git a/modules/audio_processing/include/audio_processing.h b/modules/audio_processing/include/audio_processing.h
index 457d97a..50ec430 100644
--- a/modules/audio_processing/include/audio_processing.h
+++ b/modules/audio_processing/include/audio_processing.h
@@ -23,11 +23,11 @@
 #include <vector>
 
 #include "api/audio/echo_canceller3_config.h"
+#include "api/audio/echo_control.h"
 #include "api/optional.h"
 #include "modules/audio_processing/beamformer/array_util.h"
 #include "modules/audio_processing/include/audio_processing_statistics.h"
 #include "modules/audio_processing/include/config.h"
-#include "modules/audio_processing/include/echo_control.h"
 #include "rtc_base/arraysize.h"
 #include "rtc_base/deprecation.h"
 #include "rtc_base/platform_file.h"