migrate Theobroma Systems mail addresses to CHERRY Embedded Solutions

See
https://embedded.cherry.de/theobroma-systems-is-now-officially-part-of-cherry-se/



While the mail addresses on the theobroma-systems.com domain should be
redirect to cherry.de, let's anticipate IT hiccups and avoid important
mails not reaching us by swapping the domain name wherever appropriate
for the newer one.

Christoph Mueller isn't working at ~Theobroma~ CHERRY Embedded Solutions
anymore, but I don't know his new mail address so mails destined to him
will keep bouncing.

Cc: Heiko Stuebner <heiko.stuebner@cherry.de> <heiko.stuebner@theobroma-systems.com>
Cc: Jakob Unterwurzacher <jakob.unterwurzacher@cherry.de>
Cc: Klaus Goger <klaus.goger@cherry.de>
Signed-off-by: Quentin Schulz <quentin.schulz@cherry.de>