vk/formats: Fix incorrect depth formats

vk/formats: Fix incorrect depth formats

anv_format::surface_format was incorrect for Vulkan depth formats.
For example, the format table mapped

    VK_FORMAT_D24_UNORM -> .surface_format = D24_UNORM_X8_UINT
    VK_FORMAT_D32_FLOAT -> .surface_format = D32_FLOAT

but should have mapped

    VK_FORMAT_D24_UNORM -> .surface_format = R24_UNORM_X8_TYPELESS
    VK_FORMAT_D32_FLOAT -> .surface_format = R32_FLOAT

The Crucible test func.depthstencil.basic passed despite the bug, but
only because it did not attempt to texture from the depth surface.

The core problem is that RENDER_SURFACE_STATE.SurfaceFormat and
3DSTATE_DEPTH_BUFFER.SurfaceFormat are distinct types. Considering them
as enum spaces, the two enum spaces have incompatible collisions.

Fix this by adding a new field 'depth_format' to struct anv_format.

Refer to brw_surface_formats.c:translate_tex_format() for precedent.