feat(ff-a): allow ffa_run forwarding to secure world.

An ffa_run is needed when there are secondary secure parititions with
multiple execution contexts. Power management does not wake up those
execution contexts into their wait loops, so an ffa_run is necessary.
This is similar to the infrastructure tf-a-tests has to enable running
multiple secure partitions.

Signed-off-by: Raghu Krishnamurthy <raghu.ncstate@gmail.com>
Change-Id: I95e13040a42ab2833ec9267520cb1c099a7d41a1
diff --git a/src/api.c b/src/api.c
index 9d0a37b..d08e3f8 100644
--- a/src/api.c
+++ b/src/api.c
@@ -760,6 +760,10 @@
 		goto out;
 	}
 
+	if (plat_ffa_run_forward(vm_id, vcpu_idx, &ret)) {
+		return ret;
+	}
+
 	/* The requested VM must exist. */
 	vm = vm_find(vm_id);
 	if (vm == NULL) {