platform/x86: fujitsu-laptop: sanitize hotkey input device identification

In the case of brightness-related FUJ02B1 ACPI device, initializing the
input device associated with it identically as acpi-video initializes
its input device makes sense.  However, using the same data for the
input device associated with the FUJ02E3 ACPI device makes little sense,
because the latter has nothing to do with video and assigning an
arbitrary product ID to it is redundant.

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