v3dv: implement interpolation qualifiers

Also, Vulkan uses the same provoking vertex rules are Direct3D, which
changes from OpenGL's default. Make sure we honor that.

Fixes:
dEQP-VK.spirv_assembly.instruction.graphics.cross_stage.*

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6766>
2 files changed