hw/arm/mps2: Update old infocenter.arm.com URLs

hw/arm/mps2: Update old infocenter.arm.com URLs

Update old infocenter.arm.com URLs to the equivalent developer.arm.com
ones (the old URLs should redirect, but we might as well avoid the
redirection notice, and the new URLs are pleasantly shorter).

This commit covers the links to the MPS2 board TRM, the various
Application Notes, the IoTKit and SSE-200 documents.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210215115138.20465-25-peter.maydell@linaro.org