drm/xe/ptl: Add HuC FW definition for PTL

Add the unversioned define for the PTL HuC FW.

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://lore.kernel.org/r/20250626182805.1701096-15-daniele.ceraolospurio@intel.com