net: add endianness annotations to ethernet headers

net: add endianness annotations to ethernet headers

Spotted by sparse in OVS build:

/home/runner/work/ovs/ovs/dpdk-dir/build/include/rte_flow.h:789:27:
error: incorrect type in initializer (different base types)
/home/runner/work/ovs/ovs/dpdk-dir/build/include/rte_flow.h:789:27:
expected unsigned short [usertype] ether_type
/home/runner/work/ovs/ovs/dpdk-dir/build/include/rte_flow.h:789:27:
got restricted ovs_be16 [usertype]
/home/runner/work/ovs/ovs/dpdk-dir/build/include/rte_flow.h:829:25:
error: incorrect type in initializer (different base types)
/home/runner/work/ovs/ovs/dpdk-dir/build/include/rte_flow.h:829:25:
expected unsigned short [usertype] vlan_tci
/home/runner/work/ovs/ovs/dpdk-dir/build/include/rte_flow.h:829:25:
got restricted ovs_be16 [usertype]
/home/runner/work/ovs/ovs/dpdk-dir/build/include/rte_flow.h:830:26:
error: incorrect type in initializer (different base types)
/home/runner/work/ovs/ovs/dpdk-dir/build/include/rte_flow.h:830:26:
expected unsigned short [usertype] eth_proto
/home/runner/work/ovs/ovs/dpdk-dir/build/include/rte_flow.h:830:26:
got restricted ovs_be16 [usertype]

This was not caught before as no code in headers was using those fields.
This changed with commit 6f2168b69aee ("ethdev: reuse ethernet header
definition in flow item") and commit a56a262e3408 ("ethdev: reuse VLAN
header definition in flow item").

Signed-off-by: David Marchand <david.marchand@redhat.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>