Now that we have multiplatform support, let the RealView
defconfigs select all the RealView boards so we boot out of
the box like before. This updates both defconfigs.

Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>