powerpc: Make the NR_CPUS max 8192

We can compile and boot with NR_CPUS=8192, so make this the max.  1024
was an arbitrary decision anyway.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/platforms/Kconfig.cputype

@@ -262,8 +262,8 @@ config SMP
 	  If you don't know what to do here, say N.
 
 config NR_CPUS
-	int "Maximum number of CPUs (2-1024)"
-	range 2 1024
+	int "Maximum number of CPUs (2-8192)"
+	range 2 8192
 	depends on SMP
 	default "32" if PPC64
 	default "4"