contrib/gitdm: add Amazon to the domain map

contrib/gitdm: add Amazon to the domain map

We have multiple contributors from both .co.uk and .com versions of
the address. Also add .de for completeness sake.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Cc: Alexander Graf <graf@amazon.com>
Cc: Paul Durrant <pdurrant@amazon.com>
Cc: David Wooodhouse <dwmw@amazon.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Paul Durrant <pdurrant@amazon.com>
Reviewed-by: Alexander Graf <graf@amazon.com>
Message-Id: <20230315174331.2959-29-alex.bennee@linaro.org>