docbooks: fix fatal filename errors

Fix docbook fatal errors (file location changed):

docproc: lin2628-rc1/include/asm-x86/io_32.h: No such file or directory
make[1]: *** [Documentation/DocBook/deviceiobook.xml] Error 1

docproc: lin2628-rc1/include/asm-x86/atomic_32.h: No such file or directory
make[1]: *** [Documentation/DocBook/kernel-api.xml] Error 1

docproc: lin2628-rc1/include/asm-x86/mca_dma.h: No such file or directory
make[1]: *** [Documentation/DocBook/mcabook.xml] Error 1

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