V4L/DVB (6283): videobuf: Remove references to old Kconfig option name

CONFIG_VIDEO_BUF_DVB became CONFIG_VIDEOBUF_DVB.

But in these cases, it makes more sense to use CONFIG_VIDEO_SAA7134_DVB
or CONFIG_VIDEO_CX88_DVB_MODULE depending on the driver.

The reference in cx23885.h should just be removed, as the code there needs to
be included if DVB is on or off.  I do not think you can even compile the
cx23885 driver without DVB.  It's clearly just leftover from when the file was
obvious copied from the cx88 driver (which is not mentioned in the copyright
BTW).

Signed-off-by: Trent Piepho <xyzzy@speakeasy.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>