media: cec: core: disable adapter in cec_devnode_unregister

[ Upstream commit fe4526d9

 ]

Explicitly disable the CEC adapter in cec_devnode_unregister()

Usually this does not really do anything important, but for drivers
that use the CEC pin framework this is needed to properly stop the
hrtimer. Without this a crash would happen when such a driver is
unloaded with rmmod.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>