Remove backwards compatibile imports

This saves 80 or so bytes when frozen into the CPX build

Author: tannewt

adafruit_lis3dh.py

@@ -33,14 +33,8 @@
 import time
 import math
 import digitalio
-try:
-    from collections import namedtuple
-except ImportError:
-    from ucollections import namedtuple
-try:
-    import struct
-except ImportError:
-    import ustruct as struct
+from collections import namedtuple
+import struct
 
 from micropython import const