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/inc/vmapi/hf/ffa.h b/inc/vmapi/hf/ffa.h
index 25b1bf9..7471178 100644
--- a/inc/vmapi/hf/ffa.h
+++ b/inc/vmapi/hf/ffa.h
@@ -247,12 +247,12 @@
 	return (int32_t)val.arg2;
 }
 
-static inline ffa_vm_id_t ffa_msg_send_sender(struct ffa_value args)
+static inline ffa_vm_id_t ffa_sender(struct ffa_value args)
 {
 	return (args.arg1 >> 16) & 0xffff;
 }
 
-static inline ffa_vm_id_t ffa_msg_send_receiver(struct ffa_value args)
+static inline ffa_vm_id_t ffa_receiver(struct ffa_value args)
 {
 	return args.arg1 & 0xffff;
 }