net/mlx5: add flow validation of eCPRI header

When creating a flow with eCPRI header item, the validation of it is
mandatory. The detailed limitations are listed below:
  1. Over Ether / VLAN, ethertype must be 0xAEFE.
  2. No tunnel support is described in the specification now.
  3. L3 layer is only supported when L4 is UDP, see #4.
  4. Over TCP is not supported from the specification, and over UDP
     is not supported right now.
  5. Concatenation indicator matching is not supported now.
  6. No need to check the revision.
  7. Only type field in the common header is mandatory, and one byte
     should be matched integrally.
  8. Fields in the message payload header are optional.
  9. Only messages with type #0, #2 and #5 are supported now.

Some limitations are only from software right now, because there is
no need to support all the message types and variants of protocol
stack listed in the specification.

Signed-off-by: Bing Zhao <bingz@mellanox.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>