Clean up and remove unused code

adafruit_platformdetect/chip.py

@@ -27,11 +27,6 @@ class Chip:
     """Attempt detection of current chip / CPU."""
     def __init__(self, detector):
         self.detector = detector
-        try:
-            if os.environ['BLINKA_NOVA']:
-                self._binho = None
-        except KeyError: # no relevant environment var
-            pass
 
     @property
     def id(self): # pylint: disable=invalid-name,too-many-branches,too-many-return-statements