[media] xc4000: added card_type

This patch adds support for selecting a card type in struct
xc4000_config, to allow for implementing some card specific code
in the driver.

Signed-off-by: Istvan Varga <istvan_v@mailbox.hu>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>