coresight: docs: Create common sub-directory for coresight trace.

There are two files in the Documentation/trace directory relating to
coresight, with more to follow, so create a Documentation/trace/coresight
directory and move existing files there. Fixup index to reference
new location.

Update MAINTAINERS to reference this sub-directory rather than the
individual files.

Signed-off-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
diff --git a/MAINTAINERS b/MAINTAINERS
index dada80b..2904dac 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1610,8 +1610,7 @@
 L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
 S:	Maintained
 F:	drivers/hwtracing/coresight/*
-F:	Documentation/trace/coresight.rst
-F:	Documentation/trace/coresight-cpu-debug.rst
+F:	Documentation/trace/coresight/*
 F:	Documentation/devicetree/bindings/arm/coresight.txt
 F:	Documentation/devicetree/bindings/arm/coresight-cpu-debug.txt
 F:	Documentation/ABI/testing/sysfs-bus-coresight-devices-*