media: cec: core: disable adapter in cec_devnode_unregister

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>

media: cec: use call_op and check for !unregistered

Use call_(void_)op consistently in the CEC core framework. Ditto
for the cec pin ops. And check if !adap->devnode.unregistered before
calling each op. This avoids calls to ops when the device has been
unregistered and the underlying hardware may be gone.

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

media: cec: move the core to a separate directory

In preparation for moving CEC drivers to the CEC directory,
move the core to a separate place.

Acked-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>