drm/i915/mtl: Skip pcode qgv restrictions for MTL

Communicating QGV points restriction to PUnit happens via PM Demand
instead of the Pcode mailbox in the previous platforms. GV point
restriction is handled by the PM demand code.

Signed-off-by: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Reviewed-by: Vinod Govindapillai <vinod.govindapillai@intel.com>
Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230318005852.2303937-5-radhakrishna.sripada@intel.com