[media] cxd2820: convert get|set_fontend to use DVBv5 parameters

[media] cxd2820: convert get|set_fontend to use DVBv5 parameters

Instead of using dvb_frontend_parameters struct, that were
designed for a subset of the supported standards, use the DVBv5
cache information.

Also, fill the supported delivery systems at dvb_frontend_ops
struct.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>