ethdev: add min/max MTU to device info

ethdev: add min/max MTU to device info

This addresses the usability issue raised by OVS at DPDK Userspace
summit. It adds general min/max MTU into device info. For compatibility,
and to save space, it fits in a hole in existing structure.

The initial version sets max MTU to normal Ethernet, it is up to
PMD to set larger value if it supports Jumbo frames.

Also remove the deprecation notice introduced in 18.11 regarding this
change and bump ethdev ABI version.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Ian Stokes <ian.stokes@intel.com>
Acked-by: Andrew Rybchenko <arybchenko@solarflare.com>
Reviewed-by: Ferruh Yigit <ferruh.yigit@intel.com>