added freebsd cross-compile to 'make check' tests

License: MIT
Signed-off-by: Rob Deutsch <rdeutschob@gmail.com>

mk/util.mk

@@ -20,6 +20,8 @@ SUPPORTED_PLATFORMS += linux-amd64
 SUPPORTED_PLATFORMS += darwin-386
 SUPPORTED_PLATFORMS += darwin-amd64
 
+SUPPORTED_PLATFORMS += freebsd-amd64
+
 space:=
 space+=
 comma:=,