feat(rng_trap): add tests for FEAT_RNG_TRAP

Added 2 tests that expect a trap to be triggered when a read is
performed on:
1. RNDR register
2. RNDRRS register
The result will be a panic signal and the whole system will halt,
as there is no handler set for such trap.

Signed-off-by: Juan Pablo Conde <juanpablo.conde@arm.com>
Change-Id: Ia979e60a106b394cc09dfdf94115354fb72142d1
diff --git a/tftf/tests/tests-rndr_trap.mk b/tftf/tests/tests-rndr_trap.mk
new file mode 100644
index 0000000..147b704
--- /dev/null
+++ b/tftf/tests/tests-rndr_trap.mk
@@ -0,0 +1,9 @@
+#
+# Copyright (c) 2022, Arm Limited. All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+TESTS_SOURCES	+=	$(addprefix tftf/tests/,			\
+	extensions/rng_trap/test_rndr_trap.c				\
+)