power_key: unbind the touchscreen driver when the screen is off
since the touchscreen currently keeps on running while the screen is off. Why not unbind it in our power_key loop:
for the phone, that's writing 2-0038
to /sys/bus/i2c/drivers/edt_ft5x06/unbind
(and of course bind), and if that doesn't work on the devkit, I wouldn't bother...