Add the unversioned define for the LNL HuC FW.

All new binaries are GSC-enabled (and even if they weren't the driver
can detect the type of HuC binary), so the new lnl HuC filename doesn't
use the _gsc postfix to avoid confusion with the GSC binary.
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240725003224.516233-5-daniele.ceraolospurio@intel.com