drm/i915/dmc: Load DMC on MTL

Add support to load DMC on MTL.

According to the spec and based on tests done on real hardware, 0x7000
is a reasonable size limit that covers each possible payload.

v2:
  - Tighten payload size limit. (Matt, Rodrigo)
  - Use a better name for the defined payload limit. (Rodrigo)

Signed-off-by: Madhumitha Tolakanahalli Pradeep <madhumitha.tolakanahalli.pradeep@intel.com>
Signed-off-by: Gustavo Sousa <gustavo.sousa@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Anusha Srivatsa <anusha.srivatsa@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230307195111.90767-1-gustavo.sousa@intel.com