MLBEDSW-3653: Fix type errors in annotated files

This commit corrects a number of type errors
reported by mypy and refactors some parts of
the code which are no longer necessary after
making adjustments to satisfy mypy.

Signed-off-by: Dwight Lidman <dwight.lidman@arm.com>
Change-Id: I16b880b228e57f2a92fb8936f53e94886e0f9f44
diff --git a/ethosu/vela/data_type.py b/ethosu/vela/data_type.py
index a4b7b53..3ad642a 100644
--- a/ethosu/vela/data_type.py
+++ b/ethosu/vela/data_type.py
@@ -16,6 +16,7 @@
 # Description:
 # Defines the basic numeric type classes for tensors.
 import enum
+from typing import Any
 
 from .numeric_util import round_up_divide
 
@@ -43,6 +44,34 @@
 
     __slots__ = "type", "bits"
 
+    int8: Any
+    int16: Any
+    int32: Any
+    int64: Any
+    uint8: Any
+    uint16: Any
+    uint32: Any
+    uint64: Any
+    quint4: Any
+    quint8: Any
+    quint12: Any
+    quint16: Any
+    quint32: Any
+    qint4: Any
+    qint8: Any
+    qint12: Any
+    qint16: Any
+    qint32: Any
+    float16: Any
+    float32: Any
+    float64: Any
+    string: Any
+    bool: Any
+    resource: Any
+    variant: Any
+    complex64: Any
+    complex128: Any
+
     def __init__(self, type_, bits):
         self.type = type_
         self.bits = bits