MAINTAINERS: list the section entries in the preferred order

MAINTAINERS: list the section entries in the preferred order

The MAINTAINERS file header has never shown a preferred order for the
section entries but scripts/parse-maintainers.pl added a preferred order
with commit 3d9eff2ab1db ("parse-maintainers: Add section pattern
sorting")

Commit 6af6f9c625f7 ("parse-maintainers: Do not sort section content by
default") changed the preferred order to be a bit more sensible.

Update the MAINTAINERS section description block to use this preferred
section entry ordering.

Add a slightly better description for the N: entry too.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: http://lkml.kernel.org/r/5aa5aad6fb1678230c260337dc066cd449a2bf32.camel@perches.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>