Defines starting with `e' in arch/i386/netboot

• EMARF arch/i386/netboot/asm.h:47
• ETH_ADDRSIZE arch/i386/netboot/ether.h:17
• ETHTYPE_ARP arch/i386/netboot/ether.h:30
• ETHTYPE_IP arch/i386/netboot/ether.h:29
• ETHTYPE_RARP arch/i386/netboot/ether.h:31