MAINTAINERS: update Robert Foss' email address

Update the email address for Robert's maintainer entries and fill in
.mailmap accordingly.

Link: https://lkml.kernel.org/r/20230106152151.115648-1-robert.foss@linaro.org


Signed-off-by: Robert Foss <rfoss@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Colin Ian King <colin.i.king@gmail.com>
Cc: Kalle Valo <kvalo@kernel.org>
Cc: Kirill Tkhai <tkhai@ya.ru>
Cc: Qais Yousef <qyousef@layalina.io>
Cc: Vasily Averin <vasily.averin@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>