drm/xe: Remove xe_uc_fini_hw

xe_uc_init_hw() is called multiple times from xe_gt.c,
and that makes the name xe_uc_fini_hw(), called for a different
reason in xe_guc.c confusing.

Remove it and inline the xe_uc_sanitize_reset into xe_guc.c directly.

Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://lore.kernel.org/r/20250619104858.418440-23-dev@lankhorst.se


Signed-off-by: Maarten Lankhorst <dev@lankhorst.se>