Move ANS to aom_dsp.

That's where it lives in aom/master.

Change-Id: I38f405827d9c2d0b06ef5f3bfd7cadc35d5991ef
diff --git a/av1/decoder/bitreader.h b/av1/decoder/bitreader.h
index aaf1bb8..4d77664 100644
--- a/av1/decoder/bitreader.h
+++ b/av1/decoder/bitreader.h
@@ -17,7 +17,7 @@
 #include "./aom_config.h"
 
 #if CONFIG_ANS
-#include "av1/common/ans.h"
+#include "aom_dsp/ans.h"
 #include "aom/aomdx.h"  // for av1_decrypt_cb
 #define aom_reader struct AnsDecoder
 #define aom_reader_has_error ans_reader_has_error
diff --git a/av1/decoder/detokenize.c b/av1/decoder/detokenize.c
index 778bf12..fbcf8fe 100644
--- a/av1/decoder/detokenize.c
+++ b/av1/decoder/detokenize.c
@@ -12,7 +12,9 @@
 #include "aom_mem/aom_mem.h"
 #include "aom_ports/mem.h"
 
-#include "av1/common/ans.h"
+#if CONFIG_ANS
+#include "aom_dsp/ans.h"
+#endif  // CONFIG_ANS
 #include "av1/common/blockd.h"
 #include "av1/common/common.h"
 #include "av1/common/entropy.h"
diff --git a/av1/decoder/detokenize.h b/av1/decoder/detokenize.h
index de9ded9..69d6fab 100644
--- a/av1/decoder/detokenize.h
+++ b/av1/decoder/detokenize.h
@@ -13,7 +13,9 @@
 #define AV1_DECODER_DETOKENIZE_H_
 
 #include "av1/decoder/decoder.h"
-#include "av1/common/ans.h"
+#if CONFIG_ANS
+#include "aom_dsp/ans.h"
+#endif  // CONFIG_ANS
 #include "av1/common/scan.h"
 
 #ifdef __cplusplus