feat(notifications): hypervisor forward bind/unbind

Hypervisor forwards call to SPMC of bind/unbind interfaces, when
the specified sender is an SP.
This will be useful for testing notifications with both hypervisor and
SPMC.

Change-Id: I62c44211f251a84d6bdc459bbe6b8d4fb2571933
Signed-off-by: J-Alves <joao.alves@arm.com>
diff --git a/src/api.c b/src/api.c
index 7b615ce..37a6ca9 100644
--- a/src/api.c
+++ b/src/api.c
@@ -2599,6 +2599,13 @@
 		return ffa_error(FFA_INVALID_PARAMETERS);
 	}
 
+	if (plat_ffa_notifications_update_bindings_forward(
+		    receiver_vm_id, sender_vm_id, flags, notifications, is_bind,
+		    &ret)) {
+		dlog_verbose("Forwarding call to other world.\n");
+		return ret;
+	}
+
 	if (notifications == 0U) {
 		dlog_verbose("No notifications have been specified.\n");
 		return ffa_error(FFA_INVALID_PARAMETERS);