drm: Fix deadlock due to getconnector locking changes

drm: Fix deadlock due to getconnector locking changes

In commit ccfc08655d5fd5076828f45fb09194c070f2f63a
Author: Rob Clark <[email protected]>
Date:   Thu Dec 18 16:01:48 2014 -0500

    drm: tweak getconnector locking

We need to extend the locking to cover connector->state reading for
atomic drivers, but the above commit was a bit too eager and also
included the fill_modes callback. Which on i915 on old platforms using
load detection needs to acquire modeset locks, resulting in a deadlock
on output probing.

Reported-by: Marc Finet <[email protected]>
Cc: Marc Finet <[email protected]>
Cc: [email protected]
Signed-off-by: Daniel Vetter <[email protected]>
Reviewed-by: Rob Clark <[email protected]>
Signed-off-by: Dave Airlie <[email protected]>