anv: Use TRANSFER_SRC_OPTIMAL for depth/stencil MSAA resolves

anv: Use TRANSFER_SRC_OPTIMAL for depth/stencil MSAA resolves

As of 52ad1712ed62, TRANSFER_SRC_OPTIMAL and SHADER_READ_ONLY_OPTIMAL
are now identical for depth buffers so there's no reason why we need to
use the "wrong" layout.  Technically, according to Vulkan, blits and
MSAA resolves are transfer ops so we should use the transfer layout now
that we can.

Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Nanley Chery <nanley.g.chery@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/2605>