boards/raytac: Change Nordic license to Apache

For yaml files we do not normally even add a license, but if any it
should be Apache2 and not the Nordic one.
Note there is plenty of examples of yaml files very similar to this
in the Zephyr tree. So even if the author/submitter of the original
commit could have used as starting point a file from NCS, it would have
been the same if he would have used a Zephyr one.

Signed-off-by: Alberto Escolar Piedras <alberto.escolar.piedras@nordicsemi.no>

Author: aescolar

boards/raytac/an54l15q_db/raytac_an54l15q_db_nrf54l15_cpuapp_ns.yaml

@@ -1,6 +1,6 @@
 # Copyright (c) 2025 Nordic Semiconductor ASA
 # Copyright (c) 2025 Raytac Corporation.
-# SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
+# SPDX-License-Identifier: Apache-2.0
 
 identifier: raytac_an54l15q_db/nrf54l15/cpuapp/ns
 name: Raytac-AN54L15Q-DB-nRF54l15-Application-Non-Secure