Add freebsd/ppc64 support in test_crosscompile.sh (#128)

diff --git a/test_crosscompile.sh b/test_crosscompile.sh
index c736c8b..bbab6b2 100755
--- a/test_crosscompile.sh
+++ b/test_crosscompile.sh
@@ -27,7 +27,7 @@
 
 cross linux     amd64 386 arm arm64 ppc64 ppc64le s390x mips mipsle mips64 mips64le
 cross darwin    amd64 arm64
-cross freebsd   amd64 386 arm arm64
+cross freebsd   amd64 386 arm arm64 ppc64
 cross netbsd    amd64 386 arm arm64
 cross openbsd   amd64 386 arm arm64
 cross dragonfly amd64