x86_64: remove unused variable maxcpus

.. and adjust documentation to properly reflect options that are
x86-64 specific.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Documentation/x86_64/boot-options.txt

@@ -134,12 +134,6 @@ Non Executable Mappings
 
 SMP
 
-  nosmp	Only use a single CPU
-
-  maxcpus=NUMBER only use upto NUMBER CPUs
-
-  cpumask=MASK   only use cpus with bits set in mask
-
   additional_cpus=NUM Allow NUM more CPUs for hotplug
 		 (defaults are specified by the BIOS, see Documentation/x86_64/cpu-hotplug-spec)
 

arch/x86_64/kernel/mpparse.c

@@ -32,7 +32,6 @@
 
 /* Have we found an MP table */
 int smp_found_config;
-unsigned int __initdata maxcpus = NR_CPUS;
 
 /*
  * Various Linux-internal data structures created from the