doc: ReSTify Yama.txt

Adjusts for ReST markup and moves under LSM admin guide.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

security/yama/Kconfig

@@ -7,6 +7,7 @@ config SECURITY_YAMA
 	  system-wide security settings beyond regular Linux discretionary
 	  access controls. Currently available is ptrace scope restriction.
 	  Like capabilities, this security module stacks with other LSMs.
-	  Further information can be found in Documentation/security/Yama.txt.
+	  Further information can be found in
+	  Documentation/admin-guide/LSM/Yama.rst.
 
 	  If you are unsure how to answer this question, answer N.