tracing: consolidate documents

Move kmemtrace.txt, tracepoints.txt, ftrace.txt and mmiotrace.txt to
the new trace/ directory.

I didnt find any references to those documents in both source
files and documents, so no extra work needs to be done.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Pekka Paalanen <pq@iki.fi>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
LKML-Reference: <49DD6E2B.6090200@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/Documentation/ftrace.txt b/Documentation/trace/ftrace.txt
similarity index 100%
rename from Documentation/ftrace.txt
rename to Documentation/trace/ftrace.txt

diff --git a/Documentation/vm/kmemtrace.txt b/Documentation/trace/kmemtrace.txt
similarity index 100%
rename from Documentation/vm/kmemtrace.txt
rename to Documentation/trace/kmemtrace.txt

diff --git a/Documentation/tracers/mmiotrace.txt b/Documentation/trace/mmiotrace.txt
similarity index 100%
rename from Documentation/tracers/mmiotrace.txt
rename to Documentation/trace/mmiotrace.txt

diff --git a/Documentation/tracepoints.txt b/Documentation/trace/tracepoints.txt
similarity index 100%
rename from Documentation/tracepoints.txt
rename to Documentation/trace/tracepoints.txt