BACKPORT: media: Kconfig: DVB support should be enabled for Digital TV

As we reverted changeset 85f7cd3a ("Revert "media: Kconfig: better support hybrid TV devices""),
we should add a default to DVB_CORE, as otherwise DVB support won't work.

Bug: 189516917
(cherry picked from commit 8e5b5d75)
Fixes: 85f7cd3a ("Revert "media: Kconfig: better support hybrid TV devices"")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Lecopzer Chen <lecopzer.chen@mediatek.com>
Change-Id: Ifb1f2aca77e4f9904f0025af795468fb8f1d5749