Remove OpImage*Dref* from mismatch type tests

Remove OpImage*Dref* from mismatch type tests

Mismatch type group testing non-depth formats and using
OpImage*Dref* instructions with vulkan formats not having depth
component is invalid usage.

Extending the mismatch test type group to include depth/stencil
format later would require checking format features for
VK_FORMAT_FEATURE_2_SAMPLED_IMAGE_DEPTH_COMPARISON_BIT

Components: Vulkan

Affects: dEQP-VK.spirv_assembly.instruction.graphics.image_sampler.*

VK-GL-CTS issue: 4172

Change-Id: I2353e235295cff4609799e14298e6df7d6a66221