drm/i915: Pass ww ctx to intel_pin_to_display_plane

Instead of multiple lockings, lock the object once,
and perform the ww dance around attach_phys and pin_pages.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210323155059.628690-23-maarten.lankhorst@linux.intel.com