[media] xc4000: detect also xc4100

Added code to detect the XC4100 chip, which is presumably an analog-only
"value" version of the XC4000. It is not sure, however, if any devices
using this have actually been produced and sold, so the patch may be
unneeded.

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