docbook: fix rapidio warning

Fix fsl_rio.c kernel-doc warning: no exported symbols as
requested by !E are found:

Warning(arch/powerpc/sysdev/fsl_rio.c): no structured comments found

Signed-off-by: Randy Dunlap <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

Documentation/DocBook/rapidio.tmpl

···
 !Idrivers/rapidio/rio-sysfs.c
      </sect1>
      <sect1 id="PPC32_support"><title>PPC32 support</title>
-!Earch/powerpc/sysdev/fsl_rio.c
 !Iarch/powerpc/sysdev/fsl_rio.c
      </sect1>
   </chapter>