Install new fieldType property (identifier)

Problem/Motivation

Actually the new property "identifier" is not installed automatically after module update.

Steps to reproduce

• Update ephoto_dam from 8.x-3.6 to 8.x-3.7
• drush updb
• the new property is not added to field instance tables

Proposed resolution

use an appropriate hook_update_N()
I'll contribute a patch soon.