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>
          properties->filterMinmaxSingleComponentFormats = true;
          break;
       }
+      case VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_SUBGROUP_PROPERTIES: {
+         VkPhysicalDeviceSubgroupProperties *properties =
+            (VkPhysicalDeviceSubgroupProperties *)ext;
+         properties->subgroupSize = 64;
+         properties->supportedStages = VK_SHADER_STAGE_COMPUTE_BIT;
+         properties->supportedOperations = VK_SUBGROUP_FEATURE_BASIC_BIT |
+                                           VK_SUBGROUP_FEATURE_VOTE_BIT;
+         properties->quadOperationsInAllStages = false;
+         break;
+      }
 
       default:
          break;