documentation: move mtrr.txt to Doc/x86/ subdir

Move mtrr.txt to the Documentation/x86/ subdirectory.
Add 00-INDEX to the Documentation/x86/ subdirectory.

Signed-off-by: Randy Dunlap <[e-mail]>
Cc: Adrian Bunk <[e-mail]>
Signed-off-by: Ingo Molnar <[e-mail]>

Documentation/00-INDEX

···
 	- how to execute Mono-based .NET binaries with the help of BINFMT_MISC.
 moxa-smartio
 	- file with info on installing/using Moxa multiport serial driver.
-mtrr.txt
-	- how to use PPro Memory Type Range Registers to increase performance.
 mutex-design.txt
 	- info on the generic mutex subsystem.
 namespaces/

Documentation/mtrr.txt Documentation/x86/mtrr.txt

···
   The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
   MTRRs. These are supported.  The AMD Athlon family provide 8 Intel
   style MTRRs.
-  
+
   The Centaur C6 (WinChip) has 8 MCRs, allowing write-combining. These
   are supported.
 
···
 reg01: base=0xfb000000 (4016MB), size=  16MB: write-combining, count=1
 reg02: base=0xfb000000 (4016MB), size=   4kB: uncachable, count=1
 
-Some cards (especially Voodoo Graphics boards) need this 4 kB area 
+Some cards (especially Voodoo Graphics boards) need this 4 kB area
 excluded from the beginning of the region because it is used for
 registers.
 

Documentation/x86/00-INDEX

···
+00-INDEX
+	- this file
+mtrr.txt
+	- how to use x86 Memory Type Range Registers to increase performance

arch/x86/Kconfig

···
 	  You can safely say Y even if your machine doesn't have MTRRs, you'll
 	  just add about 9 KB to your kernel.
 
-	  See <file:Documentation/mtrr.txt> for more information.
+	  See <file:Documentation/x86/mtrr.txt> for more information.
 
 config MTRR_SANITIZER
 	bool