drm/xe/tlb: ensure we access seqno_recv once

Ensure we load gt->tlb_invalidation.seqno_recv once, and use that for
our seqno checking. The gt->tlb_invalidation_seqno_past is a shared
global variable and can potentially change at any point here.  However
the checks here need to operate on a stable version of seqno_recv for
this to make any sense.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: José Roberto de Souza <jose.souza@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>