V4L/DVB: Don't identify PV SBTVD Hybrid as a DibCom device

As reported by Carlos, Prolink Pixelview SBTVD Hybrid is based on
Conexant cx231xx + Fujitsu 86A20S demodulator. However, both shares
the same USB ID. So, we need to use USB bcdDevice, in order to
properly discover what's the board.

We know for sure that bcd 0x100 is used for a dib0700 device, while
bcd 0x4001 is used for a cx23102 device. This patch reserves two ranges,
the first one from 0x0000-0x3f00 for dib0700, and the second from
0x4000-0x4fff for cx231xx devices.

This may need fixes in the future, as we get access to other devices.

Thanks-to: Carlos Americo Domiciano <c_domiciano@yahoo.com.br>
Cc: stable@kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>