V4L/DVB (9473): add DVB_DEVICE_NUM and DVB_ADAPTER_NUM to uevent

This allows udev to create proper device nodes without any
hacky shell scripts/programs to call, which guess these numbers
from the kernel device names.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>