Add support for freebsd/arm64

[MikaelUrankar]

Required for all PRs:

• Signed CLA.
• Associated README.md updated.
• Has appropriate unit tests.

# Update sys, net and gopsutil to fix build failure on FreeBSD/aarch64:
github.com/influxdata/telegraf/vendor/github.com/miekg/dns/vendor/golang.org/x/net/internal/socket
vendor/github.com/miekg/dns/vendor/golang.org/x/net/internal/socket/cmsghdr.go:9:10: undefined: cmsghdr
vendor/github.com/miekg/dns/vendor/golang.org/x/net/internal/socket/cmsghdr.go:10:10: undefined: cmsghdr
vendor/github.com/miekg/dns/vendor/golang.org/x/net/internal/socket/cmsghdr.go:11:10: undefined: cmsghdr
vendor/github.com/miekg/dns/vendor/golang.org/x/net/internal/socket/cmsghdr_bsd.go:9:10: undefined: cmsghdr
vendor/github.com/miekg/dns/vendor/golang.org/x/net/internal/socket/iovec_64bit.go:12:10: undefined: iovec
vendor/github.com/miekg/dns/vendor/golang.org/x/net/internal/socket/msghdr_bsd.go:11:10: undefined: msghdr
vendor/github.com/miekg/dns/vendor/golang.org/x/net/internal/socket/msghdr_bsd.go:11:28: undefined: iovec
vendor/github.com/miekg/dns/vendor/golang.org/x/net/internal/socket/msghdr_bsd.go:26:10: undefined: msghdr
vendor/github.com/miekg/dns/vendor/golang.org/x/net/internal/socket/msghdr_bsd.go:33:10: undefined: msghdr
vendor/github.com/miekg/dns/vendor/golang.org/x/net/internal/socket/msghdr_bsd.go:37:10: undefined: msghdr
vendor/github.com/miekg/dns/vendor/golang.org/x/net/internal/socket/msghdr_bsd.go:37:10: too many errors

# github.com/influxdata/telegraf/vendor/golang.org/x/sys/unix
vendor/golang.org/x/sys/unix/ztypes_freebsd_arm64.go:400:12: undefined: uint128

# github.com/influxdata/telegraf/vendor/github.com/shirou/gopsutil/disk
vendor/github.com/shirou/gopsutil/disk/disk_freebsd.go:26:36: undefined: MNT_WAIT
vendor/github.com/shirou/gopsutil/disk/disk_freebsd.go:31:15: undefined: Statfs
vendor/github.com/shirou/gopsutil/disk/disk_freebsd.go:32:28: undefined: MNT_WAIT
vendor/github.com/shirou/gopsutil/disk/disk_freebsd.go:38:17: undefined: MNT_RDONLY
vendor/github.com/shirou/gopsutil/disk/disk_freebsd.go:41:17: undefined: MNT_SYNCHRONOUS
vendor/github.com/shirou/gopsutil/disk/disk_freebsd.go:44:17: undefined: MNT_NOEXEC
vendor/github.com/shirou/gopsutil/disk/disk_freebsd.go:154:9: undefined: Bintime
vendor/github.com/shirou/gopsutil/disk/disk_freebsd.go:163:22: undefined: Statfs
vendor/github.com/shirou/gopsutil/disk/disk_freebsd.go:167:54: undefined: Statfs
vendor/github.com/shirou/gopsutil/disk/disk_freebsd.go:182:32: undefined: Devstat
vendor/github.com/shirou/gopsutil/disk/disk_freebsd.go:44:17: too many errors

[danielnelson]

Thanks for the update, can you run go mod tidy and push, hopefully that will take care of the CI failures.

For watchers, this will require Telegraf to be built with Go 1.14. I expect this would be used with the official Telegraf 1.15 builds only.