float_dsp: ppc: add a separate header for Altivec function prototypes

Also include config.h so that HAVE_ALTIVEC will be defined.
Fixes compilation on PPC with Altivec enabled.

libavutil/ppc/float_dsp_altivec.c

@@ -19,6 +19,7 @@
  */
 
 #include "util_altivec.h"
+#include "float_dsp_altivec.h"
 
 void ff_vector_fmul_altivec(float *dst, const float *src0, const float *src1,
                             int len)

libavutil/ppc/float_dsp_altivec.h

+/*
+ * Copyright (c) 2006 Luca Barbato <lu_zero@gentoo.org>
+ *
+ * This file is part of Libav.
+ *
+ * Libav is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * Libav is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVUTIL_PPC_FLOAT_DSP_ALTIVEC_H
+#define AVUTIL_PPC_FLOAT_DSP_ALTIVEC_H
+
+extern void ff_vector_fmul_altivec(float *dst, const float *src0,
+                                   const float *src1, int len);
+
+#endif /* AVUTIL_PPC_FLOAT_DSP_ALTIVEC_H */

libavutil/ppc/float_dsp_init.c

@@ -18,11 +18,10 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#include "config.h"
 #include "libavutil/cpu.h"
 #include "libavutil/float_dsp.h"
-
-extern void ff_vector_fmul_altivec(float *dst, const float *src0,
-                                   const float *src1, int len);
+#include "float_dsp_altivec.h"
 
 void ff_float_dsp_init_ppc(AVFloatDSPContext *fdsp, int bit_exact)
 {