MAINTAINERS: Make Nicolas Saenz Julienne the new bcm2835 maintainer

Eric isn't active any more and i don't have the necessary free time.
Nicolas already made contributions to bcm2835 and is pleased to take
over the maintainership. My thanks go to both of them.

Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Acked-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>