media: ddbridge/sx8: enable modulation selection in set_parameters()

Allow for tuning to transponders with specific modulations in
set_parameters(). Setting a specific modulation will also enable lower
modulations.

Picked up from the upstream dddvb GIT. Upstream also has support for
APSK64/128/256 modulations which aren't supported yet by the DVB
API, so comment them out until support for them is added.

Signed-off-by: Daniel Scheller <d.scheller@gmx.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>