EDID is a standard that allows a sink to declare to the source what functionality it supports such as Video Resolutions, Audio, etc.
(See the EDID standard for more details.)
DisplayID is a standard targeted to replace EDID and E-EDID extensions with a uniform format suited for both PC monitor and consumer electronics devices.
(See the DisplayID Standard for more details.)
The DisplayPort IP supports IIC (I2C) over AUX, so that it can work with any IIC component such as an EDID or DisplayID.
The DisplayPort reference designs have a sample EDID which is outside of the DisplayPort IP.
It does not contain the DisplayID extensions, but it can be used as a starting point for customer applications.
The EDID is generated when you generate the example design.
If you want to add the DisplayID info then you will have to write your own code in addition to the EDID code and create a structure as per the DisplayID specification.
Because this is an IIC over AUX connection, there is no need for any modification in the DisplayPort IP.
The user will make the changes to connect it to the IIC interface.
The DisplayPort AUX transactions do not care if EDID or DisplayID is used.
Whatever the data, EDID or the DisplayID, the source should be able to read them through IIC over AUX queries.
The user application is responsible for managing the EDID or DisplayID data that is returned.