stable_kernel_rules: Add pointer to netdev-FAQ for network patches

Stable_kernel_rules should point submitters of network stable patches to the
netdev_FAQ.txt as requests for stable network patches should go to netdev
first.
Signed-off-by: Dave Chiluk <chiluk@canonical.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/stable_kernel_rules.txt

@@ -29,6 +29,9 @@ Rules on what kind of patches are accepted, and which ones are not, into the
 
 Procedure for submitting patches to the -stable tree:
 
+ - If the patch covers files in net/ or drivers/net please follow netdev stable
+   submission guidelines as described in
+   Documentation/networking/netdev-FAQ.txt
  - Send the patch, after verifying that it follows the above rules, to
    stable@vger.kernel.org.  You must note the upstream commit ID in the
    changelog of your submission, as well as the kernel version you wish