fujitsu-laptop: fix config corner case

This patch is a trivial fix for a config corner case, ensuring that
fujitsu-laptop doesn't get compiled into the kernel when the led class
is a module.

Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: Jonathan Woithe <jwoithe@physics.adelaide.edu.au>
Signed-off-by: Len Brown <len.brown@intel.com>