arm/arm64 architecture cross compilation failed

```bash
# GOOS=linux GOARCH=arm64 go build main.go
# github.com/google/gopacket/pcap
../../../../pkg/mod/github.com/google/gopacket@v1.1.20-0.20201227084530-a0bf7fd45b3d/pcap/pcap.go:30:22: undefined: pcapErrorNotActivated
../../../../pkg/mod/github.com/google/gopacket@v1.1.20-0.20201227084530-a0bf7fd45b3d/pcap/pcap.go:52:17: undefined: pcapTPtr
../../../../pkg/mod/github.com/google/gopacket@v1.1.20-0.20201227084530-a0bf7fd45b3d/pcap/pcap.go:64:10: undefined: pcapPkthdr
../../../../pkg/mod/github.com/google/gopacket@v1.1.20-0.20201227084530-a0bf7fd45b3d/pcap/pcap.go:103:6: undefined: pcapBpfProgram
../../../../pkg/mod/github.com/google/gopacket@v1.1.20-0.20201227084530-a0bf7fd45b3d/pcap/pcap.go:110:7: undefined: pcapPkthdr
../../../../pkg/mod/github.com/google/gopacket@v1.1.20-0.20201227084530-a0bf7fd45b3d/pcap/pcap.go:268:33: undefined: pcapErrorActivated
../../../../pkg/mod/github.com/google/gopacket@v1.1.20-0.20201227084530-a0bf7fd45b3d/pcap/pcap.go:269:33: undefined: pcapWarningPromisc
../../../../pkg/mod/github.com/google/gopacket@v1.1.20-0.20201227084530-a0bf7fd45b3d/pcap/pcap.go:270:33: undefined: pcapErrorNoSuchDevice
../../../../pkg/mod/github.com/google/gopacket@v1.1.20-0.20201227084530-a0bf7fd45b3d/pcap/pcap.go:271:33: undefined: pcapErrorDenied
../../../../pkg/mod/github.com/google/gopacket@v1.1.20-0.20201227084530-a0bf7fd45b3d/pcap/pcap.go:272:33: undefined: pcapErrorNotUp
../../../../pkg/mod/github.com/google/gopacket@v1.1.20-0.20201227084530-a0bf7fd45b3d/pcap/pcap.go:272:33: too many errors
```