fix(mediatek): add mt8186 plat build in CI

Signed-off-by: Manish Pandey <manish.pandey2@arm.com>
Change-Id: Iaa205c317e928f664c1d9745a7b4a0e2a3f69275
diff --git a/group/tf-l1-build-plat/mt8186-default:nil b/group/tf-l1-build-plat/mt8186-default:nil
new file mode 100644
index 0000000..35f8713
--- /dev/null
+++ b/group/tf-l1-build-plat/mt8186-default:nil
@@ -0,0 +1,5 @@
+#
+# Copyright (c) 2022 Arm Limited. All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+#