[media] DiB7090: add support for the dib7090 based

This patch adds support for the SoC DiB7090 DVB-T demodulator and its
melt-in UHF/VHF RF tuner.

Signed-off-by: Olivier Grenie <olivier.grenie@dibcom.fr>
Signed-off-by: Patrick Boettcher <patrick.boettcher@dibcom.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>