drm/i915: Introduce with_intel_display_power_if_enabled()

Add the _if_enabled() counterpart to with_intel_display_power().

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210913144440.23008-7-ville.syrjala@linux.intel.com


Reviewed-by: Jani Nikula <jani.nikula@intel.com>