drm/syncobj: Fix xa_alloc allocation flags

drm/syncobj: Fix xa_alloc allocation flags

The xarray conversion blindly and wrongly replaced idr_alloc with xa_alloc
and kept the GFP_NOWAIT. It should have been GFP_KERNEL to account for
idr_preload it removed. Fix it.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Fixes: fec2c3c01f1c ("drm/syncobj: Convert syncobj idr to xarray")
Reported-by: Himanshu Girotra <himanshu.girotra@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Himanshu Girotra <himanshu.girotra@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Tvrtko Ursulin <tursulin@ursulin.net>
Link: https://lore.kernel.org/r/20260324111019.22467-1-tvrtko.ursulin@igalia.com