Use new-style return values from spci_msg_wait and spci_msg_poll.

Bug: 141469322
Change-Id: Ib9815695537837f029c698c6966bad93c094e89e
diff --git a/inc/vmapi/hf/spci.h b/inc/vmapi/hf/spci.h
index 0883038..125380b 100644
--- a/inc/vmapi/hf/spci.h
+++ b/inc/vmapi/hf/spci.h
@@ -193,6 +193,21 @@
 	uint64_t arg7;
 };
 
+static inline spci_vm_id_t spci_msg_send_sender(struct spci_value args)
+{
+	return (args.arg1 >> 16) & 0xffff;
+}
+
+static inline spci_vm_id_t spci_msg_send_receiver(struct spci_value args)
+{
+	return args.arg1 & 0xffff;
+}
+
+static inline uint32_t spci_msg_send_size(struct spci_value args)
+{
+	return args.arg3;
+}
+
 /** SPCI common message header. */
 struct spci_message {
 	/*