ssh/terminal: add AIX operating system

This commit adds AIX operation system to ssh/terminal package.

Change-Id: I31ccec5512dbf476eaf22ff79951b5fab434d5fd
Reviewed-on: https://go-review.googlesource.com/c/151077
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
2 files changed