anv: Fix get_image_format_properties() - depthstencil (v2)
Teach it to calculate the features of depthstencil formats. The goal is to incrementally fix get_image_format_properties() to return a correct result. Currently, it returns incorrect VkFormatFeatureFlags which the caller must clean up. v2: New commit message Reviewed-by: Jason Ekstrand <jason@jlekstrand.net> (v1)