FF-A: Change name of direct message wrappers

Changed the name of 'ffa_msg_send_receiver' and 'ffa_msg_send_sender'
to 'ffa_receiver' and 'ffa_sender'. The intent is to make it
semantically more generic, so they can be used in other contexts than
FF-A direct messaging interfaces. E.g. Notifications interfaces.

Change-Id: Ibca469a5cd2af42d628fe7ac494ba07a11bd0b07
Signed-off-by: J-Alves <joao.alves@arm.com>
diff --git a/test/linux/hftest_socket.c b/test/linux/hftest_socket.c
index 9ce60c2..1ea363a 100644
--- a/test/linux/hftest_socket.c
+++ b/test/linux/hftest_socket.c
@@ -88,8 +88,8 @@
 		swap(&(hdr->src_port), &(hdr->dst_port));
 
 		/* Swap the destination and source ids. */
-		ffa_vm_id_t dst_id = ffa_msg_send_sender(ret);
-		ffa_vm_id_t src_id = ffa_msg_send_receiver(ret);
+		ffa_vm_id_t dst_id = ffa_sender(ret);
+		ffa_vm_id_t src_id = ffa_receiver(ret);
 
 		EXPECT_EQ(ffa_rx_release().func, FFA_SUCCESS_32);
 		EXPECT_EQ(