ARM: integrator: remove static AP syscon mapping

This removes the static mapping for the AP system controller for
the device tree case. Fork the static mappings table and move
the system controller to only be statically mapped in the ATAG
boot path.

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