parisc: Default to 8 CPUs for 64-bit kernel

I've now seen a 6-way SMP rp4440 machine, so increase minimum
number of CPUs to 8 for 64-bit kernels.
Signed-off-by: Helge Deller <deller@gmx.de>

arch/parisc/Kconfig

@@ -336,7 +336,7 @@ config NR_CPUS
 	int "Maximum number of CPUs (2-32)"
 	range 2 32
 	depends on SMP
-	default "4" if 64BIT
+	default "8" if 64BIT
 	default "16"
 
 config KEXEC