parisc: Suspend lockup detectors before system halt

commit 56188832 upstream.

Some machines can't power off the machine, so disable the lockup detectors to
avoid this watchdog BUG to show up every few seconds:
watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [systemd-shutdow:1]
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/parisc/kernel/process.c

@@ -50,6 +50,7 @@
 #include <linux/uaccess.h>
 #include <linux/rcupdate.h>
 #include <linux/random.h>
+#include <linux/nmi.h>
 
 #include <asm/io.h>
 #include <asm/asm-offsets.h>
@@ -142,6 +143,7 @@ void machine_power_off(void)
 
 	/* prevent soft lockup/stalled CPU messages for endless loop. */
 	rcu_sysrq_start();
+	lockup_detector_suspend();
 	for (;;);
 }