Added code to run on Power systems

[genisysram]

Hi
Here is my contribution to your code, its working good on powersystems.

Thanks for the code, its working good.

What do these changes do?

Added Architecture "ppc64le"

Are there changes in behavior for the user?

No

[vweevers]

Thanks for the PR. My response is the same as browserify/node-util#53 (comment):

Nothing about this package (or any pure-JS package that doesn't touch the filesystem) can vary based on architecture, so testing in other architectures is not valuable.

On abstract-leveldown we can guarantee we'll never introduce dependencies with native addons, or touch the filesystem, because abstract-leveldown is an abstract interface that targets both node and browsers.

Testing against ppc64le would be valuable on native addons like https://github.com/Level/leveldown.