parisc: Fix detection of nonsynchronous cr16 cycle counters

For CPUs which have an unknown or invalid CPU location (physical location)
assume that their cycle counters aren't syncronized across CPUs.

Signed-off-by: Helge Deller <deller@gmx.de>
Fixes: c8c3735 ("parisc: Enhance detection of synchronous cr16 clocksources")
Cc: stable@vger.kernel.org # 4.13+
Signed-off-by: Helge Deller <deller@gmx.de>

arch/parisc/kernel/time.c

@@ -253,7 +253,10 @@ static int __init init_cr16_clocksource(void)
 		cpu0_loc = per_cpu(cpu_data, 0).cpu_loc;
 
 		for_each_online_cpu(cpu) {
-			if (cpu0_loc == per_cpu(cpu_data, cpu).cpu_loc)
+			if (cpu == 0)
+				continue;
+			if ((cpu0_loc != 0) &&
+			    (cpu0_loc == per_cpu(cpu_data, cpu).cpu_loc))
 				continue;
 
 			clocksource_cr16.name = "cr16_unstable";