Add framework tests for tfl.atan2

Signed-off-by: Luke Hutton <luke.hutton@arm.com>
Change-Id: I11a891296a040f4e48187d0d51a4dd2c554805ac
diff --git a/verif/frameworks/test_builder.py b/verif/frameworks/test_builder.py
index e86d5fe..407902a 100644
--- a/verif/frameworks/test_builder.py
+++ b/verif/frameworks/test_builder.py
@@ -352,6 +352,13 @@
         def eval(self, a):
             return tf.math.cos(a, name=self.result_name)
 
+    class Atan2:
+        def __init__(self, name):
+            self.result_name = name
+
+        def eval(self, a, b):
+            return tf.math.atan2(a, b, name=self.result_name)
+
     class Square:
         def __init__(self, name):
             self.result_name = name