[media] xc5000: Add MODULE_FIRMWARE statements

This will make modinfo more useful with regard
to discovering necessary firmware files.

Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Michael Krufky <mkrufky@kernellabs.com>
Cc: Eddi De Pieri <eddi@depieri.net>
Cc: linux-media@vger.kernel.org
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>