cmd/objdump: disable objdump_test with external linking on GOARCH=mips{,le}

Updates #12559.

Change-Id: I5e8f4cf7071d0d71618527a6b6096e771d5eeb28
Reviewed-on: https://go-review.googlesource.com/34317Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

src/cmd/objdump/objdump_test.go

@@ -166,7 +166,7 @@ func TestDisasmExtld(t *testing.T) {
 		t.Skipf("skipping on %s, no support for external linking, issue 9038", runtime.GOARCH)
 	case "arm64":
 		t.Skipf("skipping on %s, issue 10106", runtime.GOARCH)
-	case "mips64", "mips64le":
+	case "mips64", "mips64le", "mips", "mipsle":
 		t.Skipf("skipping on %s, issue 12559 and 12560", runtime.GOARCH)
 	case "s390x":
 		t.Skipf("skipping on %s, issue 15255", runtime.GOARCH)