When allocating a buffer normally, this flag gets to the allocator from
the memory requirements, but when sparse bindings are created we were
checking for them but never setting them.
Fixes sparse descriptor buffers on Xe2.
Makes the failure on TRTT more obvious.
Fixes: c6a91f1695 ("anv: add new heap/pool for descriptor buffers")
Fixes: 692e1ab2c1 ("anv: get rid of the second dynamic state heap")
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/31372>