libmpeg2: fix ppc altivec.h detection

Patch from Gentoo.

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

package/multimedia/libmpeg2/libmpeg2-0.5.1-altivec.patch

@@ -0,0 +1,23 @@
+[PATCH] fix altivec.h detection
+
+Patch from Gentoo:
+
+http://sources.gentoo.org/cgi-bin/viewvc.cgi/gentoo-x86/media-libs/libmpeg2/files/libmpeg2-0.5.1-altivec.patch?revision=1.1&view=markup
+
+Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
+--- a/configure.ac.bak	2010-05-25 17:12:14.756245990 +0000
++++ b/configure.ac	2010-05-25 17:11:51.629581723 +0000
+@@ -79,11 +79,10 @@
+ 		 CFLAGS="$OPT_CFLAGS $TRY_CFLAGS $CFLAGS"
+ 		 AC_MSG_CHECKING([if <altivec.h> is needed])
+ 		 AC_TRY_COMPILE([],
+-		    [typedef vector int t;
+-		     vec_ld(0, (unsigned char *)0);],
++		    [vector int t; t = vec_add(t,t);],
+ 		    [have_altivec=yes; AC_MSG_RESULT(no)],
+ 		    [AC_TRY_COMPILE([#include <altivec.h>],
+-			[typedef vector int t; vec_ld(0, (unsigned char *)0);],
++			[vector int t; t = vec_add(t,t);],
+ 			[AC_DEFINE([HAVE_ALTIVEC_H],,
+ 			    [Define to 1 if you have the <altivec.h> header.])
+ 			 have_altivec=yes; AC_MSG_RESULT(yes)],

package/multimedia/libmpeg2/libmpeg2.mk

@@ -7,6 +7,7 @@ LIBMPEG2_VERSION = 0.5.1
 LIBMPEG2_SOURCE = libmpeg2-$(LIBMPEG2_VERSION).tar.gz
 LIBMPEG2_SITE = http://libmpeg2.sourceforge.net/files/
 LIBMPEG2_INSTALL_STAGING = YES
+LIBMPEG2_AUTORECONF = YES
 LIBMPEG2_CONF_OPT = --without-x --disable-directx
 
 ifeq ($(BR2_PACKAGE_SDL),y)