drm/xe/guc: Move ARAT interrupts enabling to the upload step

Even though ARAT interrupts are enabled by default, we still want
to keep the code that enables them. But instead doing that in the
CTB enabling step, move this code to the upload step, where we
already setup few other registers related to GuC.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240619163413.817-1-michal.wajdeczko@intel.com