Convert the dmc wakelock interface to struct intel_display instead of
struct drm_i915_private. We'll want to convert the intel_de interfaces,
and there's a bit of coupling between the two, so start here.

Cc: Luca Coelho <luciano.coelho@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/3c260bbbce0af8714b07157dc032b038efa3bf1c.1713358679.git.jani.nikula@intel.com