add ETH_P_MACSEC netinet/if_ether.h, new in linux v4.6
add ETH_P_MACSEC netinet/if_ether.h, new in linux v4.6

ethertype for macsec added in linux commit
dece8d2b78d19df7fe5e4e965f1f0d1a3e188d1b

chardi/musl,chardi/musl,chardi/musl