libmpeg2: fix ppc altivec.h detection

[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)],

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)