anv: Add allocator support for client-visible addresses

anv: Add allocator support for client-visible addresses

When a BO is flagged as having a client visible address, we put it in
its own heap.  We also support the client explicitly specifying an
address in said heap.  If an address collision happens, we return false
from anv_vma_alloc which turns into a VK_ERROR_OUT_OF_DEVICE_MEMORY.

Reviewed-by: Ivan Briano <ivan.briano@intel.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>