After spending months studying all the different SD Specifications
from the SD Association, voluntarily add myself as maintainer
for the SD code.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20180309153654.13518-9-f4bug@amsat.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>