drm/i915/xehp: Annotate a couple more workaround registers as MCR

GAMSTLB_CTRL and GAMCNTRL_CTRL became multicast/replicated registers on
Xe_HP.  They should be defined accordingly and use MCR-aware operations.

These registers have only been used for some dg2/xehpsdv workarounds, so
this fix is mostly just for consistency/future-proofing; even lacking
the MCR annotation, workarounds will always be properly applied in a
multicast manner on these platforms.

Cc: Gustavo Sousa <gustavo.sousa@intel.com>
Fixes: 58bc2453

 ("drm/i915: Define multicast registers as a new type")
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Gustavo Sousa <gustavo.sousa@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230125234159.3015385-3-matthew.d.roper@intel.com