fontconfig: fix pkgconfig file in cross builds.

Do not propagate sysroot paths to Cflags.

srcpkgs/fontconfig/template

@@ -1,7 +1,7 @@
 # Template build file for 'fontconfig'.
 pkgname=fontconfig
 version=2.11.1
-revision=2
+revision=3
 build_style=gnu-configure
 configure_args="--disable-static --enable-docs --with-cache-dir=/var/cache/$pkgname"
 hostmakedepends="pkg-config"
@@ -14,6 +14,12 @@ license="MIT"
 distfiles="http://www.freedesktop.org/software/fontconfig/release/$pkgname-$version.tar.bz2"
 checksum=dc62447533bca844463a3c3fd4083b57c90f18a70506e7a9f4936b5a1e516a99
 
+post_install() {
+	if [ "$CROSS_BUILD" ]; then
+		sed -i 's,\(Cflags: -I${includedir}\).*,\1,g' ${DESTDIR}/usr/lib/pkgconfig/fontconfig.pc
+	fi
+}
+
 fontconfig-devel_package() {
 	depends="${makedepends} ${sourcepkg}>=${version}_${revision}"
 	short_desc+=" - development files"