test(SMCCC): add test for SMCCC_ARCH_WORKAROUND_3

This adds SMCCC tests for SMCCC_ARCH_WORKAROUND_3 applicable for
Cortex-A57/72/73/75 introduced as part of CVE-2022-23960 mitigation.

Signed-off-by: Bipin Ravi <bipin.ravi@arm.com>
Change-Id: If56bb0a69deda9032e050bdd2de98c8c4a5becbb
diff --git a/tftf/tests/tests-cpu-extensions.mk b/tftf/tests/tests-cpu-extensions.mk
index 061ab7e..3616cf4 100644
--- a/tftf/tests/tests-cpu-extensions.mk
+++ b/tftf/tests/tests-cpu-extensions.mk
@@ -23,4 +23,5 @@
 	runtime_services/arm_arch_svc/smccc_arch_soc_id.c		\
 	runtime_services/arm_arch_svc/smccc_arch_workaround_1.c		\
 	runtime_services/arm_arch_svc/smccc_arch_workaround_2.c		\
+	runtime_services/arm_arch_svc/smccc_arch_workaround_3.c		\
 )