layers: LX250 Verify color and depth/stencil are different.
layers: LX250 Verify color and depth/stencil are different.

Validate that the color and depth/stencil attachments in a
subpass are different.

Change-Id: I0010270e50334cd1dc5b275c29c76265f570b186

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