drm/xe: Introduce IF_ARGS macro utility

drm/xe: Introduce IF_ARGS macro utility

We want to extend our macro-based KLV list definitions with new
information about the version from which given KLV is supported.
Add utility IF_ARGS macro that can be used in code generators to
emit different code based on the presence of additional arguments.

Introduce macro itself and extend our kunit tests to cover it.
We will use this macro in next patch.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Acked-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patch.msgid.link/20251217224018.3490-1-michal.wajdeczko@intel.com