system-info: Use the default multiarch tuples as a fallback for ICDs
This is similar to the behavior that we have for Vulkan Layers. The only difference is that for ICDs we still have the ability to set a custom "multiarch_tuples" parameter, without the need to set the multiarch for the whole #SrtSystemInfo object.
Fixes: #58 (closed)
Edited by Ludovico de Nittis