cpufreq: User/admin documentation update and consolidation

The user/admin documentation of cpufreq is badly outdated.  It
conains stale and/or inaccurate information along with things
that are not particularly useful.  Also, some of the important
pieces are missing from it.

For this reason, add a new user/admin document for cpufreq
containing current information to admin-guide and drop the old
outdated .txt documents it is replacing.

Since there will be more PM documents in admin-guide going forward,
create a separate directory for them and put the cpufreq document
in there right away.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/cpu-freq/index.txt

@@ -21,8 +21,6 @@ Documents in this directory:
 
 amd-powernow.txt -	AMD powernow driver specific file.
 
-boost.txt -		Frequency boosting support.
-
 core.txt	-	General description of the CPUFreq core and
 			of CPUFreq notifiers.
 
@@ -32,17 +30,12 @@ cpufreq-nforce2.txt -	nVidia nForce2 platform specific file.
 
 cpufreq-stats.txt -	General description of sysfs cpufreq stats.
 
-governors.txt	-	What are cpufreq governors and how to
-			implement them?
-
 index.txt	-	File index, Mailing list and Links (this document)
 
 intel-pstate.txt -	Intel pstate cpufreq driver specific file.
 
 pcc-cpufreq.txt -	PCC cpufreq driver specific file.
 
-user-guide.txt	-	User Guide to CPUFreq
-
 
 Mailing List
 ------------