platform/x86: fujitsu-laptop: only register platform device if FUJ02E3 is present

The platform device registered by fujitsu-laptop is registered
unconditionally while sysfs attributes attached to it depend on the
FUJ02E3 ACPI device being present.  Fix this by moving platform device
creation and removal to acpi_fujitsu_laptop_add() and
acpi_fujitsu_laptop_remove(), respectively.

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