platform/x86: fujitsu-laptop: select LEDS_CLASS

Follow common subsystem practice of selecting LEDS_CLASS instead of
riddling module code with #ifdefs.

Signed-off-by: Michał Kępień <kernel@kempniu.pl>
Reviewed-by: Jonathan Woithe <jwoithe@just42.net>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>