build(imx8ulp): add build configs for imx8ulp

Add build configs for i.MX8ULP.

Signed-off-by: Jacky Bai <ping.bai@nxp.com>
Change-Id: I40ba84037a38034c596f78718d96d0f2551e1432
diff --git a/group/tf-l1-build-plat/imx8ulp-default:nil b/group/tf-l1-build-plat/imx8ulp-default:nil
new file mode 100644
index 0000000..5515958
--- /dev/null
+++ b/group/tf-l1-build-plat/imx8ulp-default:nil
@@ -0,0 +1,6 @@
+#
+# Copyright (c) 2023 Arm Limited. All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+#
+