refactor(spm): managed exit tests

Factored out code to enable managed exit interrupt for a given SP, to
reuse it in the context of testing the Schedule Receiver Interrupt
SWd behavior, in the context of notifications feature work.

Signed-off-by: J-Alves <joao.alves@arm.com>
Change-Id: Idcecd486c7a952f0842ebf90c274adcea9e30152
diff --git a/include/common/test_helpers.h b/include/common/test_helpers.h
index eaea72c..8220244 100644
--- a/include/common/test_helpers.h
+++ b/include/common/test_helpers.h
@@ -352,4 +352,9 @@
 test_result_t spm_run_multi_core_test(uintptr_t cpu_on_handler,
 				      event_t *cpu_booted);
 
+/**
+ * Enable/Disable managed exit interrupt for the provided SP.
+ */
+bool spm_set_managed_exit_int(ffa_id_t sp_id, bool enable);
+
 #endif /* __TEST_HELPERS_H__ */