rockchip: puma/lion: update MAINTAINERS file

Philipp does not work at Theobroma Systems anymore so let's swap
Philipp's address with mine.

Cc: Philipp Tomsich <philipp.tomsich@vrull.eu>
Cc: Quentin Schulz <foss+u-boot@0leil.net>
Signed-off-by: Quentin Schulz <quentin.schulz@theobroma-systems.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@vrull.eu>