This commit fills out VkPhysicalDeviceSubgroupProperties if present
in a VkPhysicalDeviceProperties2. The values here are simply pulled
from the blob.
Fixes some flakes in dEQP-VK.subgroups.* since dEQP was reading
uninitialized values of VkPhysicalDeviceSubgroupProperties.
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5564>