drm/i915: Take modeset locks around intel_modeset_setup_hw_state()

drm/i915: Take modeset locks around intel_modeset_setup_hw_state()

commit 027476642811f8559cbe00ef6cc54db230e48a20 upstream.

Some lower level things get angry if we don't have modeset locks
during intel_modeset_setup_hw_state(). Actually the resume and
lid_notify codepaths alreday hold the locks, but the init codepath
doesn't, so fix that.

Note: This slipped through since we only disable pipes if the
plane/pipe linking doesn't match. Which is only relevant on older
gen3 mobile machines, if the BIOS fails to set up our preferred
linking.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Tested-and-reported-by: Paul Bolle <pebolle@tiscali.nl>
[danvet: Add note now that I could confirm my theory with the log
files Paul Bolle provided.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>