Add myself as maintainer for ST-Ericsson U8500 SoC to MAINTAINERS.
Linus Walleij usually reviews all Ux500 related patches,
so add him as a reviewer.

Cc: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: NStephan Gerhold <stephan@gerhold.net>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>