drm/i915: Pass acquire ctx also to intel_release_load_detect_pipe()

For now this is not necessary since intel_set_mode() doesn't acquire any
new locks. However, once that function is converted to atomic, that will
change, since we'll pass an atomic state to it, and that needs to have
the right acquire context set.

Signed-off-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>