MAINTAINERS: Update Raspberry Pi development repository

Eric Anholt's repo isn't used anymore. List current one.

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