Revert "i915: Update MTL DMC v2.22"

This reverts commit 8a9be67bd7.

We detected a regression associated with MTL DMC v2.22. So let's revert
it back to v2.21 until we have a new release with the fix.

Signed-off-by: Gustavo Sousa <gustavo.sousa@intel.com>

WHENCE

@@ -5022,7 +5022,7 @@ File: i915/mtl_dmc_ver2_10.bin
 Version: DMC API/APB ver 2 release 10 for Meteorlake
 
 File: i915/mtl_dmc.bin
-Version: DMC API/APB ver 2 release 22 for Meteorlake
+Version: DMC API/APB ver 2 release 21 for Meteorlake
 
 File: i915/mtl_guc_70.bin
 Version: GuC API/APB ver 70.29.2 for Meteorlake