docs: Add rest label the_canonical_patch_format

In preparation to convert Documentation/network/netdev-FAQ.rst to
restructured text format.  We would like to be able to reference 'the
canonical patch format' section.

Add rest label: 'the_canonical_patch_format'.

Signed-off-by: Tobin C. Harding <me@tobin.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/Documentation/process/submitting-patches.rst b/Documentation/process/submitting-patches.rst
index 908bb55..c091710 100644
--- a/Documentation/process/submitting-patches.rst
+++ b/Documentation/process/submitting-patches.rst
@@ -611,6 +611,7 @@
 method for indicating a bug fixed by the patch. See :ref:`describe_changes`
 for more details.
 
+.. _the_canonical_patch_format:
 
 14) The canonical patch format
 ------------------------------