core: drivers: relicense hisi_trng.c as BSD-2-Clause

The file core/drivers/hisi_trng.c should not have been committed with a
GPL-2.0 license. Relicense it as BSD-2-Clause.

Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org>
Reported-by: Sahil Malhotra <sahil.malhotra@nxp.com>
Closes: OP-TEE#6834

core/drivers/hisi_trng.c

@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0
+// SPDX-License-Identifier: BSD-2-Clause
 /* Copyright (c) 2023 HiSilicon Limited. */
 
 #include <initcall.h>