docbook/mcabook: fixup x86 path/file names

Fix docbook templates for new x86 path/filenames:
docproc: linux-2.6.23-git2/include/asm-i386/mca_dma.h: No such file or directory
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Documentation/DocBook/mcabook.tmpl

@@ -101,7 +101,7 @@
 
   <chapter id="dmafunctions">
      <title>DMA Functions Provided</title>
-!Iinclude/asm-i386/mca_dma.h
+!Iinclude/asm-x86/mca_dma.h
   </chapter>
 
 </book>