Update spci_msg_send to new SPCI beta API.

This removes the header in the message buffers, as the header data is now
passed in the SPCI_MSG_SEND parameters.

Bug: 141469322
Change-Id: I3a61f5470fd95ba2d47df33f5c96466ba286af85
diff --git a/src/arch/aarch64/hypervisor/handler.c b/src/arch/aarch64/hypervisor/handler.c
index 00ba80b..c4719ab 100644
--- a/src/arch/aarch64/hypervisor/handler.c
+++ b/src/arch/aarch64/hypervisor/handler.c
@@ -324,7 +324,11 @@
 
 		return true;
 	case SPCI_MSG_SEND_32:
-		args->func = api_spci_msg_send(args->arg1, current(), next);
+		*args = api_spci_msg_send(spci_msg_send_sender(*args),
+					  spci_msg_send_receiver(*args),
+					  spci_msg_send_size(*args),
+					  spci_msg_send_attributes(*args),
+					  current(), next);
 		return true;
 	case SPCI_MSG_WAIT_32:
 		*args = api_spci_msg_recv(true, current(), next);