doc: netlink: specs: tc: add multi-attr to tc-taprio-sched-entry

Add multi-attr attribute to tc-taprio-sched-entry to specify multiple
entries.
Signed-off-by: Alessandro Marcolini <alessandromarcolini99@gmail.com>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/0ba5088ea715103a2bce83b12e2dcbdaa08da6ac.1706962013.git.alessandromarcolini99@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Documentation/netlink/specs/tc.yaml

@@ -3376,6 +3376,7 @@ attribute-sets:
         name: entry
         type: nest
         nested-attributes: tc-taprio-sched-entry
+        multi-attr: true
   -
     name: tc-taprio-sched-entry
     attributes: