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

drivers/gpu/drm/i915/display/intel_dmc.c

@@ -89,10 +89,13 @@ static struct intel_dmc *i915_to_dmc(struct drm_i915_private *i915)
 	__stringify(major) "_"			\
 	__stringify(minor) ".bin"
 
+#define XELPDP_DMC_MAX_FW_SIZE		0x7000
 #define DISPLAY_VER13_DMC_MAX_FW_SIZE	0x20000
-
 #define DISPLAY_VER12_DMC_MAX_FW_SIZE	ICL_DMC_MAX_FW_SIZE
 
+#define MTL_DMC_PATH			DMC_PATH(mtl)
+MODULE_FIRMWARE(MTL_DMC_PATH);
+
 #define DG2_DMC_PATH			DMC_LEGACY_PATH(dg2, 2, 08)
 MODULE_FIRMWARE(DG2_DMC_PATH);
 
@@ -995,7 +998,10 @@ void intel_dmc_init(struct drm_i915_private *i915)
 
 	INIT_WORK(&dmc->work, dmc_load_work_fn);
 
-	if (IS_DG2(i915)) {
+	if (IS_METEORLAKE(i915)) {
+		dmc->fw_path = MTL_DMC_PATH;
+		dmc->max_fw_size = XELPDP_DMC_MAX_FW_SIZE;
+	} else if (IS_DG2(i915)) {
 		dmc->fw_path = DG2_DMC_PATH;
 		dmc->max_fw_size = DISPLAY_VER13_DMC_MAX_FW_SIZE;
 	} else if (IS_ALDERLAKE_P(i915)) {