fujitsu-laptop: better handling of P8010 hotkey

This patch (mostly from Peter Gruber) improves the handling of the hotkeys
for P8010 laptops by passing more accurate input events back to userspace.
This is needed because the P8010 labels these buttons quite differently to
earlier laptops.  As part of this, a P8010-specific DMI callback check has
been implemented.  Finally there's some minor whitespace cleanups from
running the source through Lindent.

Signed-off-by: Peter Gruber <nokos@gmx.net>
Signed-off-by: Jonathan Woithe <jwoithe@physics.adelaide.edu.au>
Signed-off-by: Len Brown <len.brown@intel.com>