hw/arm/virt: Add serial aliases in DTB

hw/arm/virt: Add serial aliases in DTB

If there is more than one UART in the DTB, then there is no guarantee
on which order a guest is supposed to initialise them.  The standard
solution to this is "serialN" entries in the "/aliases" node of the
dtb which give the nodename of the UARTs.

At the moment we only have two UARTs in the DTB when one is for
the Secure world and one for the Non-Secure world, so this isn't
really a problem. However if we want to add a second NS UART we'll
need the aliases to ensure guests pick the right one.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-id: 20240610162343.2131524-2-peter.maydell@linaro.org