EA-PHP 5.3 and lower are not available in the WHM Feature Manager.
When editing a feature list, even if earlier versions of EA-PHP are installed on the server, only EA-PHP 5.4 and above are shown as selectable features.
We've opened an internal case for our development team to investigate this further. For reference, the case number is CPANEL-39628. Follow this article to receive an email notification when a solution is published to the product.
Use PHP 5.4 or higher.