kstrto*: add documentation

As Bruce Fields pointed out, kstrto* is currently lacking kerneldoc
comments.  This patch adds kerneldoc comments to common variants of
kstrto*: kstrto(u)l, kstrto(u)ll and kstrto(u)int.

Signed-off-by: Eldad Zack <eldad@fogrefinery.com>
Cc: J. Bruce Fields <bfields@fieldses.org>
Cc: Joe Perches <joe@perches.com>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Rob Landley <rob@landley.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/Documentation/DocBook/kernel-api.tmpl b/Documentation/DocBook/kernel-api.tmpl
index 00687ee..f75ab4c 100644
--- a/Documentation/DocBook/kernel-api.tmpl
+++ b/Documentation/DocBook/kernel-api.tmpl
@@ -58,6 +58,9 @@
 
      <sect1><title>String Conversions</title>
 !Elib/vsprintf.c
+!Finclude/linux/kernel.h kstrtol
+!Finclude/linux/kernel.h kstrtoul
+!Elib/kstrtox.c
      </sect1>
      <sect1><title>String Manipulation</title>
 <!-- All functions are exported at now