initialize net_mode.if_type

if_type is not correctly initialized

Failure to initialize if_type means that grub2/efinet sends
a bogus arp request. It therefore gets no response. On Raspberry Pi 3B+
this leads to a pause at:

lan78xx_eth Waiting for PHY auto negotiation to complete....... done
lan78xx_eth Waiting for PHY auto negotiation to complete....... done

Signed-off-by: Andrew Thomas <andrew.thomas@oracle.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>

lib/efi_loader/efi_net.c

@@ -361,6 +361,7 @@ efi_status_t efi_net_register(void)
 	memcpy(netobj->net_mode.current_address.mac_addr, eth_get_ethaddr(), 6);
 	netobj->net_mode.hwaddr_size = ARP_HLEN;
 	netobj->net_mode.max_packet_size = PKTSIZE;
+	netobj->net_mode.if_type = ARP_ETHER;
 
 	netobj->pxe.mode = &netobj->pxe_mode;
 	if (dhcp_ack)