hw/arm/armsse: Support dual-CPU configuration

hw/arm/armsse: Support dual-CPU configuration

The SSE-200 has two Cortex-M33 CPUs. These see the same view
of memory, with the exception of the "private CPU region" which
has per-CPU devices. Internal device interrupts for SSE-200
devices are mostly wired up to both CPUs, with the exception of
a few per-CPU devices. External GPIO inputs on the SSE-200
device are provided for the second CPU's interrupts above 32,
as is already the case for the first CPU.

Refactor the code to support creation of multiple CPUs.
For the moment we leave all CPUs with the same view of
memory: this will not work in the multiple-CPU case, but
we will fix this in the following commit.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190121185118.18550-12-peter.maydell@linaro.org