doc: fix broken references

There are numerous broken references to Documentation files (in other
Documentation files, in comments, etc.). These broken references are
caused by typo's in the references, and by renames or removals of the
Documentation files. Some broken references are simply odd.

Fix these broken references, sometimes by dropping the irrelevant text
they were part of.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

Documentation/timers/highres.txt

@@ -30,7 +30,7 @@ hrtimer base infrastructure
 ---------------------------
 
 The hrtimer base infrastructure was merged into the 2.6.16 kernel. Details of
-the base implementation are covered in Documentation/hrtimers/hrtimer.txt. See
+the base implementation are covered in Documentation/timers/hrtimers.txt. See
 also figure #2 (OLS slides p. 15)
 
 The main differences to the timer wheel, which holds the armed timer_list type