vela: Minor refactor

 - Changed comments to docstring on QuantizationParams
 - Simplified op type to op name conversion

Signed-off-by: Tim Hall <tim.hall@arm.com>
Change-Id: I2fdf5922cc17944c9bd37917a85fdfe50a1e651d
diff --git a/ethosu/vela/vela.py b/ethosu/vela/vela.py
index 63cccc5..efe8edb 100644
--- a/ethosu/vela/vela.py
+++ b/ethosu/vela/vela.py
@@ -42,7 +42,7 @@
 from .tensor import Tensor
 from .tflite.Model import Model
 from .tflite_mapping import builtin_operator_map
-from .tflite_mapping import builtin_type_name
+from .tflite_mapping import builtin_operator_name_map
 from .tflite_model_semantic import TFLiteSemantic
 from .tflite_supported_operators import TFLiteSupportedOperators
 from .tosa_model_semantic import TosaSemantic
@@ -230,7 +230,7 @@
             raise ValueError
 
         op_constraint_links = []
-        op_list = sorted(((op, builtin_type_name(op)) for op in builtin_operator_map), key=lambda x: x[1])
+        op_list = sorted(((op, builtin_operator_name_map[op]) for op in builtin_operator_map), key=lambda x: x[1])
         for op, name in op_list:
             internal_op = builtin_operator_map[op][0]
             if internal_op in TFLiteSupportedOperators.supported_operators: