platform/x86: fujitsu-laptop: remove keycode fields from struct fujitsu_bl

Remove the keycode[1-5] fields from struct fujitsu_bl as they are not
needed any more as a result of the sparse keymap migration.

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