media: dvb: update buffer mmaped flags and frame counter

Now that we have support for a buffer counter and for
error flags, update them at DMX_DQBUF.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: move dvb kAPI headers to include/media

Except for DVB, all media kAPI headers are at include/media.

Move the headers to it.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>