docs: submitting-patches: clarify the role of LKML

The documentation previously stated that LKML should be used as *last
resort*. However, scripts/get_maintainer.pl always suggests it and in a
discussion about changing that[0] it turned out that LKML should in fact
receive all patches.

Update documentation to make it clear that all patches should be sent to
LKML by default, in addition to any subsystem-specific lists.

[0]: https://lore.kernel.org/lkml/19a701a8d5837088aa7d8ba594c228c0e040e747.camel@perches.com/Signed-off-by: Hannu Hartikainen <hannu@hrtk.in>
Link: https://lore.kernel.org/r/20210707133634.286840-1-hannu@hrtk.inSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/process/submitting-patches.rst

@@ -216,11 +216,11 @@ cannot find a maintainer for the subsystem you are working on, Andrew
 Morton (akpm@linux-foundation.org) serves as a maintainer of last resort.
 
 You should also normally choose at least one mailing list to receive a copy
-of your patch set.  linux-kernel@vger.kernel.org functions as a list of
-last resort, but the volume on that list has caused a number of developers
-to tune it out.  Look in the MAINTAINERS file for a subsystem-specific
-list; your patch will probably get more attention there.  Please do not
-spam unrelated lists, though.
+of your patch set.  linux-kernel@vger.kernel.org should be used by default
+for all patches, but the volume on that list has caused a number of
+developers to tune it out.  Look in the MAINTAINERS file for a
+subsystem-specific list; your patch will probably get more attention there.
+Please do not spam unrelated lists, though.
 
 Many kernel-related lists are hosted on vger.kernel.org; you can find a
 list of them at http://vger.kernel.org/vger-lists.html.  There are