Almost no PowerVR devices satisfy minimum Vulkan requirements #3631

Please see #1069 (comment) for the Vulkan gpuinfo query results.

We should look into this a bit more closely and see if these are reasonable devices to support and whether we can tighten some limits to allow them.

• Update the correspondence doc with whatever we do here, and in the Vulkan column, take maxFragmentCombinedOutputResources into account in all of the limits it affects.