radv: add support for sampler2DViewOf3D
GFX8 always supports sampler2DViewOf3D. GFX9+ seems to work fine after the switch to set RADEON_SURF_2D_VIEW_COMPAT
.
Tested with dEQP-VK.pipeline.monolithic.image_2d_view_3d_image.*
on GFX8/GFX9/GFX10 APUs.