Mouse detection bug

[skiv71]

Hi, great application!

I've noticed a bug when deploying this application in fydeos, but on reviewing the source, I see a possible bug in the -M choices 0,1,2.

I've not seen this issue on fedora, ubuntu etc and even brunch, but I think it must be down to the driver being used.

Basically, in 0 (default) the code was missing my: -

/dev/input/by-id/pci-0000:00:15.0-platform-i2c_designware.0-event-mouse -> ../event9

I think it relates to https://github.com/alexmohr/keyboard-backlight/blob/master/kbd_backlight.cpp#L473

I was able to workaround by specifying -m 1 (internal only), but really, option 0 should pick this up.