I haven't seen any installation notes specific to PHP for this version.
I'd try with FastCGI (See Introduction to Oracle HTTP Server (12c Release 2 (12.1.2)))
Testing this is on my To-do list; I was hoping to get around to it before replying, but ...
OTN has posted my new article on installing PHP with Oracle HTTP Server. See http://www.oracle.com/technetwork/articles/dsl/jones-php-ohs-2194096.html
I will delete my older speculative technical messages in this thread.