hw/arm: Correctly disable FPU/DSP for some ARMSSE-based boards

hw/arm: Correctly disable FPU/DSP for some ARMSSE-based boards

The SSE-200 hardware has configurable integration settings which
determine whether its two CPUs have the FPU and DSP:
 * CPU0_FPU (default 0)
 * CPU0_DSP (default 0)
 * CPU1_FPU (default 1)
 * CPU1_DSP (default 1)

Similarly, the IoTKit has settings for its single CPU:
 * CPU0_FPU (default 1)
 * CPU0_DSP (default 1)

Of our four boards that use either the IoTKit or the SSE-200:
 * mps2-an505, mps2-an521 and musca-a use the default settings
 * musca-b1 enables FPU and DSP on both CPUs

Currently QEMU models all these boards using CPUs with
both FPU and DSP enabled. This means that we are incorrect
for mps2-an521 and musca-a, which should not have FPU or DSP
on CPU0.

Create QOM properties on the ARMSSE devices corresponding to the
default h/w integration settings, and make the Musca-B1 board
enable FPU and DSP on both CPUs. This fixes the mps2-an521
and musca-a behaviour, and leaves the musca-b1 and mps2-an505
behaviour unchanged.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 20190517174046.11146-5-peter.maydell@linaro.org