This patch makes the driver return the correct DTV_DELIVERY_SYSTEM.

The driver previously returned SYS_UNDEFINED for DTV_DELIVERY_SYSTEM property,
as it lacked any driver specific S2API support.
Signed-off-by: NAkihiro Tsukada <tskd2@yahoo.co.jp>
Signed-off-by: NDouglas Schilling Landgraf <dougsland@redhat.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>