Fix up pylint method could be a function (no-self-use) warning

The introduction of the _pynq_id() method triggered this warning
from pylint, annotate accordingly.

Author: pmundt

adafruit_platformdetect/board.py

@@ -234,6 +234,7 @@ def _pine64_id(self):
             board = boards.PINEPHONE
         return board
 
+    # pylint: disable=no-self-use
     def _pynq_id(self):
         """Try to detect the id for Xilinx PYNQ boards."""
         try: