hw/arm/armsse: Add SSE-300 support

hw/arm/armsse: Add SSE-300 support

Now we have sufficiently parameterised the code, we can add SSE-300
support by adding a new entry to the armsse_variants[] array.

Note that the main watchdog (unlike the s32k watchdog) in the SSE-300
is a different device from the CMSDK watchdog; we don't have a model
of it so we leave it as a TYPE_UNIMPLEMENTED_DEVICE stub.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210219144617.4782-36-peter.maydell@linaro.org