Move daala_fdct4() / daala_idct4() into daala_tx.c.

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Change-Id: I218f2a95542ae68491d2844becf6018eda529a1f
diff --git a/av1/common/daala_tx.h b/av1/common/daala_tx.h
index 16ab4c5..061876f 100644
--- a/av1/common/daala_tx.h
+++ b/av1/common/daala_tx.h
@@ -1,8 +1,12 @@
 #ifndef AOM_DSP_DAALA_TX_H_
 #define AOM_DSP_DAALA_TX_H_
 
+#include "aom_dsp/aom_dsp_common.h"
 #include "av1/common/odintrin.h"
 
+void daala_fdct4(const tran_low_t *input, tran_low_t *output);
+void daala_idct4(const tran_low_t *input, tran_low_t *output);
+
 void od_bin_fdct4(od_coeff y[4], const od_coeff *x, int xstride);
 void od_bin_idct4(od_coeff *x, int xstride, const od_coeff y[4]);
 void od_bin_fdst4(od_coeff y[4], const od_coeff *x, int xstride);