multimedia/pHash: add new port

PR: 202635
Submitted by: Naram Qashat <cyberbotx@cyberbotx.com>

pHash is an open source software library released under the GPLv3 license that
implements several perceptual hashing algorithms, and provides a C-like API to
use those functions in your own programs. pHash itself is written in C++.

http://phash.org/