RDMA/efa: Remove unused syndrome enum values

The notification syndrome enum values are unused, remove them.

Link: https://lore.kernel.org/r/20210126120702.9807-6-galpress@amazon.com


Reviewed-by: Firas JahJah <firasj@amazon.com>
Signed-off-by: Gal Pressman <galpress@amazon.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>