Convert lnbp21.h into a linux kernel module.
Fix up previous users to use it.
Convert dvb-ttusb-budget to use it.
Signed-off-by: NAndrew de Quincey <adq_dvb@lidskialf.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>