All buttons on the Netgear R6220 are active-low while they are flagged
as active-high.
The GPIO status reads the following for no buttons pressed:
root@64367-r6220:~# cat /sys/kernel/debug/gpio
gpio-7 ( |wps ) in hi
gpio-8 ( |wifi ) in hi
gpio-14 ( |reset ) in hi
Signed-off-by: David Bauer <mail@david-bauer.net>
(cherry picked from commit f7f9fe5256ebb660d3160452c3c01a9eb080938f)