ARM: SoC: convert VExpress/RealView to SMP operations

Convert both Realview and VExpress to use struct smp_operations to
provide their SMP and CPU hotplug operation.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>