package/python-rpi-gpio: enable package on aarch64

Enable the python-rpi-gpio package on 64-bit ARM architectures. I've tested
this with a Raspberry Pi 4 64-bit and Python 3 build and it works as expected.

Signed-off-by: Mirza Kapetanovic <mirza.kapetanovic@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>