V4L/DVB (8972): initial driver for af9015 chipset

- initial driver for the Afatech AF9015 chipset

Thanks-to: Mark Spieth <mark@digivation.com.au>
Thanks-to: Lee Essen <lee.essen@nowonline.co.uk>
Thanks-to: Luca Olivetti <luca@ventoso.org>
Thanks-to: Andrew Leech <andrew@floppyspongeonline.com>
Thanks-to: Nick Andrew <nick-linuxtv@nick-andrew.net>
Thanks-to: Rafael Antoniello <rafael.antoniello@gmail.com>
Thanks-to: Jarryd Beck <jarro.2783@gmail.com>
Thanks-to: Jose Alberto Reguero <jareguero@telefonica.net>
Thanks-to: Benjamin Larsson <banan@ludd.ltu.se>
Thanks-to: Wolfgang Breyha <wbreyha@gmx.net>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>