stockfish: enable build on ppc64 targets

srcpkgs/stockfish/template

@@ -3,8 +3,8 @@ pkgname=stockfish
 version=10
 revision=1
 wrksrc="${pkgname}-${version}-src"
-build_wrksrc=src
 create_wrksrc=yes
+build_wrksrc=src
 build_style=gnu-makefile
 make_build_target=build
 hostmakedepends="unzip"
@@ -35,6 +35,9 @@ case $XBPS_TARGET_MACHINE in
 	armv7*)
 		make_build_args+="ARCH=armv7"
 		;;
+	ppc64*)
+		make_build_args+="ARCH=ppc-64"
+		;;
 esac
 
 do_install() {