Add success64_noargs helper function

Change-Id: I54770878ebe9edaff30d9e5146fbfbf8395a756d
Signed-off-by: Tomás González <tomasagustin.gonzalezorlando@arm.com>
diff --git a/src/lib.rs b/src/lib.rs
index 659e85f..fda75d4 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1203,6 +1203,14 @@
         }
     }
 
+    /// Helper function to create an `FFA_SUCCESS` interface without any arguments.
+    pub fn success64_noargs() -> Self {
+        Self::Success {
+            target_info: 0,
+            args: SuccessArgs::Result64([0, 0, 0, 0, 0, 0]),
+        }
+    }
+
     /// Helper function to create an `FFA_ERROR` interface with an error code.
     pub fn error(error_code: FfaError) -> Self {
         Self::Error {