ethdev: introduce dump API

ethdev: introduce dump API

Added the ethdev dump API which provides querying private info from device.
There exists many private properties in different PMD drivers, such as
adapter state, Rx/Tx func algorithm in hns3 PMD. The information of these
properties is important for debug. As the information is private, the new
API is introduced.

Signed-off-by: Min Hu (Connor) <humin29@huawei.com>
Acked-by: Morten Brørup <mb@smartsharesystems.com>
Acked-by: Ray Kinsella <mdr@ashroe.eu>
Acked-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
Acked-by: Ferruh Yigit <ferruh.yigit@intel.com>