[media] em28xx: include model number for PCTV 330e

Given how PCTV has multiple products with the same model name, include the
model number in the description and #define to make it a little more clear.

Signed-off-by: Devin Heitmueller <dheitmueller@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>