Consider ID_INPUT_POINTINGSTICK as touchpad

Most resistive touchpads don't support ABS coordination nor multitouch.
When both capabilities are absent, the touchpad gets tagged as
ID_INPUT_MOUSE.

Since there's no such device as I2C mouse, if the touchpad is on I2C
bus, it will also get tagged as ID_INPUT_POINTINGSTICK.

To really distinguish a true pointing stick and a resistive touchpad,
the parser needs to find the slibling node created by HID Report
Descriptor and ensure it's a "touchpad" (i.e. ABS or MT capability).
It's not easy to traverse to a sibling node in the current parser, so
simply treat ID_INPUT_POINTINGSTICK as resistive touchpad to resolve the
issue.

checkbox-support/checkbox_support/parsers/tests/test_udevadm.py

@@ -1125,6 +1125,10 @@ def test_CRYPTO_FDE_UC20(self):
         self.assertEqual(len(devices), 93)
         self.assertEqual(self.count(devices, "PARTITION"), 1)
 
+    def test_RESISTIVE_TOUCHPAD(self):
+        devices = self.parse("RESISTIVE_TOUCHPAD")
+        self.assertEqual(self.count(devices, "TOUCHPAD"), 1)
+
     def test_two_dms_one_with_ubutnu_save(self):
         """
         This test checks that udevadm parser properly handles the case