Fix Inkplate 6 Color touchpads

[zachstence]

Expected behavior:
Examples/Inkplate6COLOR/touchpads.py should work on the Inkplate 6 Color out of the box

Actual behavior:
The following error occurs:

Traceback (most recent call last):
  File "<stdin>", line 24, in <module>
AttributeError: 'Inkplate' object has no attribute 'TOUCH1'

Problem:
The GPIO pins were not being correctly initialized for the Inkplate 6 Color

Solution:
Remove self.setPCALForLowPower() as this sets all GPIO pins to output. We want the touchpads to be input.
Initialize TOUCH1, TOUCH2, and TOUCH3 to use GPIO pins 10, 11, and 12 respectively (all in pull-up input mode).

Previously, SD_ENABLE was assigned pin 10, but that corresponds to touchpad 1. I moved SD_ENABLE to pin 13 as that is where it is on the Inkplate 6 Plus. I'm not sure if this is correct as I've been unable to find a circuit schematic for the Inkplate 6 Color.

[mkj]

This works for me