hw/misc, hw/ssi: Fix some URLs for AMD / Xilinx models

It seems that the url changed a bit, and it triggers an error.  Fix the URLs so
the documentation can be reached again.

Signed-off-by: Frederic Konrad <fkonrad@amd.com>
Reviewed-by: Francisco Iglesias <francisco.iglesias@amd.com>
Message-id: 20231124143505.1493184-3-fkonrad@amd.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
5 files changed