[media] Realtek RTL28xxU serie DVB USB interface driver

For now it supports only Realtek RTL2831U chip.
RTL2831U is integrated DVB USB interface and DVB-T demod.
DVB-T demod integrated to RTL2831U is Realtek RTL2830.
Supported tuners are QT1010, MT2060 and MXL5005S.

Signed-off-by: Antti Palosaari <crope@iki.fi>
[mchehab@redhat.com: fix a small typo]
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>