Mips64el

[bltavares]

Partially related to #3401
One of the arguments presented on the past issue is the lack of images on those architectures.

Debian provides a mips64le image as an official package, and it would be useful for embedded development to be able to run docker containers using qemu to validate programs, not only through cross-compilation.

Hopefully, this would also help to ship this to Docker for Windows - docker/for-win#10223 - I'm not sure what's the connection between those projects tho.

- What I did
I've added mips64le support to binfmt files that I found in the project

- How I did it
I followed the examples of #3518

- How to verify it
I don't know how to compile linuxkit, but I guess that if we can run docker run --platform linux/mips64le mips64le/debian:10 echo hello world we are successfull

- Description for the changelog
Includes mips64le as part of binfmt support

- A picture of a cute animal (not mandatory but encouraged)

[wanghuaiqing2010]

@bltavares
1)Please merge the two commits to one commit.
2)Your commit must be correctly signed off.

You have 2 commits incorrectly signed off. To fix, first ensure you have a local copy of your branch by checking out the pull request locally via command line. Next, head to your local branch and run:

git rebase HEAD~2 --signoff

Now your commits will have your sign off. Next run

git push --force-with-lease origin mips64el

Commit sha: 443f251, Author: Bruno Tavares, Committer: GitHub; The sign-off is missing.
Commit sha: 4ab7019, Author: Bruno Tavares, Committer: GitHub; The sign-off is missing.