[media] dib7000p: setup dev.parent for i2c master built into 7000p

We need to set the dev.parent member on the dib7000p on its i2c master, or
else calls to request_firmware() will hit an oops in 2.6.31.

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