mtrack: enabled logind server managed fd

Xorg 1.16 introduces rootless X which means that this module fails to open its file as it doesn't have permission. 

I attempted to fix this by switching to using the server fd's which are pulled from logind. 

This works except it doesn't resume correctly after a VT switch. It seems X isn't calling device_on method in a rootless session (I'm not entirely sure it would work if it did). So don't merge this yet I've just put this up in case someone has an idea how to fix that.