[media] dvbdev: remove two dead functions if !CONFIG_MEDIA_CONTROLLER_DVB

Those functions are used only if CONFIG_MEDIA_CONTROLLER_DVB.
Without that, if !CONFIG_MEDIA_CONTROLLER_DVB, it would produce
two warnings:

drivers/media/dvb-core/dvbdev.c:219:12: warning: 'dvb_create_tsout_entity' defined but not used [-Wunused-function]
 static int dvb_create_tsout_entity(struct dvb_device *dvbdev,
            ^
drivers/media/dvb-core/dvbdev.c:264:12: warning: 'dvb_create_media_entity' defined but not used [-Wunused-function]
 static int dvb_create_media_entity(struct dvb_device *dvbdev,
            ^

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