[pkg-go] Bug#1059192: ethflux: add build support for loongarch64

[zhangdandan]

Source: ethflux
Version: 1.0-4
Severity: wishlist
Tags: patch
User: debian-loongarch at lists.debian.org
Usertags: loong64

Dear maintainers,

We need to add build support for loongarch64 in d/control, for examples,
```
Package: ethflux
-Architecture: amd64 arm64 armel armhf i386 mips mips64el mipsel ppc64el 
riscv64 s390x
+Architecture: amd64 arm64 armel armhf i386 loong64 mips mips64el mipsel 
ppc64el riscv64 s390x
```

If you have any questions, you can contact me at any time.

thanks,
Dandan Zhang