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: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>