drm/xe: Remove pointless gen11 assertions

xe driver doesn't really work in gen11. Stop asserting for >= 11,
as it would likely explode anyway if tried on such platforms.

Reviewed-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
Reviewed-by: Tejas Upadhyay <tejas.upadhyay@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250306-drop-gen-v1-1-03683e56006a@intel.com


Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>