media: mantis: Kconfig: add depends on DVB_CORE for MANTIS_CORE

media: mantis: Kconfig: add depends on DVB_CORE for MANTIS_CORE

MANTIS_CORE needs DVB_CORE, set 'depends on' explicitly

ERROR: modpost: "dvb_dmx_init" [drivers/media/pci/mantis/mantis_core.ko] undefined!
ERROR: modpost: "dvb_unregister_adapter" [drivers/media/pci/mantis/mantis_core.ko] undefined!
ERROR: modpost: "dvb_register_frontend" [drivers/media/pci/mantis/mantis_core.ko] undefined!
ERROR: modpost: "dvb_ca_en50221_camchange_irq" [drivers/media/pci/mantis/mantis_core.ko] undefined!
ERROR: modpost: "dvb_unregister_frontend" [drivers/media/pci/mantis/mantis_core.ko] undefined!
>> ERROR: modpost: "dvb_ca_en50221_camready_irq" [drivers/media/pci/mantis/mantis_core.ko] undefined!
>> ERROR: modpost: "dvb_frontend_detach" [drivers/media/pci/mantis/mantis_core.ko] undefined!
>> ERROR: modpost: "dvb_dmxdev_release" [drivers/media/pci/mantis/mantis_core.ko] undefined!
>> ERROR: modpost: "dvb_dmx_swfilter" [drivers/media/pci/mantis/mantis_core.ko] undefined!

Link: https://lore.kernel.org/linux-media/20220516171515.16404-2-lecopzer.chen@mediatek.com
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Lecopzer Chen <lecopzer.chen@mediatek.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>