layers: Fix image aspect checks
layers: Fix image aspect checks

Previously validation required DS images to have both DEPTH and STENCIL
aspect bits set, but spec only requires that at least one is set.
Also, we weren't checking case of depth or stencil only formats, or
color format to make sure that correct aspect mask was set.

KhronosGroup/Vulkan-Tools,KhronosGroup/Vulkan-Tools,KhronosGroup/Vulkan-Tools,KhronosGroup/Vulkan-Tools