ARM: ux500: add SCU and WD to device tree

The Ux500 like other Cortex-A9 SoC's has a Snoop Control
Unit (SCU) and a Watchdog in the same address range as
the local timers. Add these to the SoC device tree.

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