switch: Find file descriptor path from /proc/bus/input/devices
switch: Find file descriptor path from /proc/bus/input/devices

Since IR support was removed, switches now need to read events
from /dev/input/event0 instead of /dev/input/event1 previously.
IR support will be added at one point, which means that this
path is going to change again.
This commit retrieves the right event file from
/proc/bus/input/devices such that it will automatically
read from the right file.

Signed-off-by: Francois Berder <0eabc3e9da54407da074ac08d4217d54f5b94915@imgtec.com>

francois-berder/LetMeCreate,francois-berder/LetMeCreate