[media] rtl28xxu: dynamic USB ID support

DVB USB core refuses to	load driver when current USB ID
does not match IDs on driver table. Due to that dynamic
IDs does not work. Replace reference design ID by dynamic
ID in .probe() in order to get it working.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>