MAINTAINERS: remove the obsolete section EMBEDDED LINUX

By now, many developers are working on Linux for embedded systems.  There
is no need to point out single developers.  The linux-embedded mailing
list has only little traffic, and most of it is just spam.

Remove this obsolete section.

Link: https://lkml.kernel.org/r/20230308150625.28732-1-lukas.bulwahn@gmail.com


Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Acked-by: David Woodhouse <dwmw2@infradead.org>
Cc: Olivia Mackall <olivia@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>