min max mtu size definitions mostly for drivers.
new in linux commits a52ad514fdf3b8a57ca4322c92d2d8d5c6182485 and
d894be57ca92c8a8819ab544d550809e8731137b
ETH_P_HSR (IEC 62439-3 HSRv1) added in
linux 4.7 commit ee1c27977284907d40f7f72c2d078d709f15811f
ETH_P_TSN (IEEE 1722) added in
linux 4.3 commit 1ab1e895492d8084dfc1c854efacde219e56b8c1
this constant breaks the ascending order to match the kernel header
ETH_P_XDSA (Multiplexed DSA protocol) added in
linux 3.18 commit 3e8a72d1dae374cf6fc1dba97cec663585845ff9
ETH_P_80221 is ethertype for IEEE Std 802.21 - Media Independent Handover Protocol
introduced in linux 3.15 commit b62faf3cdc875a1ac5a10696cf6ea0b12bab1596
ETH_P_LOOPBACK is the correct packet type for loopback in IEEE 802.3*
introduced in linux 3.15 commit 61ccbb684421d374fdcd7cf5d6b024b06f03ce4e
some defines were shuffled to be in ascending order and match the kernel header