devel/etcd32: fix build on riscv64

[fuz]

Summary

devel/etcd32: fix build on riscv64

Bump golang.org/x/sys and github.com/coreos/bbolt to versions that
support riscv64-freebsd.

Sponsored by:   Berliner Linux User Group e.V.
Approved by:    portmgr (build fix blanket)
Approved by:    ... (mentor)

Test Plan

Tested manually on riscv64 FreeBSD 13.1.
Tested with Poudriere on arm64 i386 amd64 FreeBSD 12.4 13.1.
See http://fuz.su/~fuz/freebsd/batch6

[eduardo]

no PORTREVISION bump needed, no pkg were built.