ethdev: remove flow metadata symbol aliases

Version aliases for rte_flow_dynf_metadata_register
and EXPERIMENTAL version on rte_flow_dynf_metadata_offs
and rte_flow_dynf_metadata_mask symbols added in
commit 56045d198968 ("ethdev: add aliases for flow metadata symbols")
are not needed after ABI version bump.
This patch removes them.

Signed-off-by: Dariusz Sosnowski <dsosnowski@nvidia.com>
Acked-by: David Marchand <david.marchand@redhat.com>