powerpc/pseries: reset the RCU watchdogs after a LPM

The RCU watchdog timer should be reset when restarting the CPU after a
Live Partition Mobility operation.
Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com>
Acked-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Combine comments into a single comment block]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221125173204.15329-1-ldufour@linux.ibm.com

arch/powerpc/platforms/pseries/mobility.c

@@ -635,10 +635,13 @@ static int do_join(void *arg)
 		prod_others();
 	}
 	/*
-	 * Execution may have been suspended for several seconds, so
-	 * reset the watchdog.
+	 * Execution may have been suspended for several seconds, so reset
+	 * the watchdogs. touch_nmi_watchdog() also touches the soft lockup
+	 * watchdog.
 	 */
+	rcu_cpu_stall_reset();
 	touch_nmi_watchdog();
+
 	return ret;
 }