doc/x86: fix doc subdirs

The Documentation/i386 and Documentation/x86_64 directories and their
contents have been moved into Documentation/x86. Fix references to
those files accordingly.

Signed-off-by: Uwe Hermann <uwe@hermann-uwe.de>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Documentation/x86/x86_64/boot-options.txt

@@ -35,7 +35,7 @@ APICs
 
    nolapic	 Don't use the local APIC (alias for i386 compatibility)
 
-   pirq=...	 See Documentation/i386/IO-APIC.txt
+   pirq=...	 See Documentation/x86/i386/IO-APIC.txt
 
    noapictimer	 Don't set up the APIC timer
 
@@ -139,7 +139,7 @@ Non Executable Mappings
 SMP
 
   additional_cpus=NUM Allow NUM more CPUs for hotplug
-		 (defaults are specified by the BIOS, see Documentation/x86_64/cpu-hotplug-spec)
+		 (defaults are specified by the BIOS, see Documentation/x86/x86_64/cpu-hotplug-spec)
 
 NUMA
 

Documentation/x86/x86_64/fake-numa-for-cpusets

@@ -10,7 +10,7 @@ amount of system memory that are available to a certain class of tasks.
 For more information on the features of cpusets, see Documentation/cpusets.txt.
 There are a number of different configurations you can use for your needs.  For
 more information on the numa=fake command line option and its various ways of
-configuring fake nodes, see Documentation/x86_64/boot-options.txt.
+configuring fake nodes, see Documentation/x86/x86_64/boot-options.txt.
 
 For the purposes of this introduction, we'll assume a very primitive NUMA
 emulation setup of "numa=fake=4*512,".  This will split our system memory into