drm/i915/adlp: Stop calling gen12lp_init_clock_gating()

The only programming that happens in gen12lp_init_clock_gating is for
display workarounds that are specific to display version 12 and are not
relevant to ADL-P's display version 13.

Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230906234732.3728630-8-matthew.d.roper@intel.com