drm/i915/mtl: Update workaround 14018778641

WA 14018778641 needs an update after recent
performance data on MTL, aligning driver here with
HW WA update.

Signed-off-by: Tejas Upadhyay <tejas.upadhyay@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230619090326.3039040-1-tejas.upadhyay@intel.com