Fix dEQP-VK.renderpass.multisample tests with depth/stencil formats

Fix dEQP-VK.renderpass.multisample tests with depth/stencil formats

Remove attachment blend state for d/s images on pipeline creation

Spec says (on VkPipelineColorBlendStateCreateInfo):
"attachmentCount is the number of VkPipelineColorBlendAttachmentState
elements in pAttachments. This value must equal the colorAttachmentCount
for the subpass in which this pipeline is used."

Affects:
dEQP-VK.renderpass.multisample.*

Components: Vulkan

VK-GL-CTS issue: 568

Change-Id: If589e5f6e06cfdf490d85fc410dc5d4381cab701