According to the users on Reddit, it's possible to get support for Google's Daydream VR platform onto the Nexus 5X, and potentially other device which are running on Android 7.0 Nougat software. Having said that, this isn't official support from Google or the manufacturers so there is no guaranteeing that it will work for any phone or device that has Android 7.0 Nougat software installed. It's also worth mentioning that some users may have varied results compared to the original poster even if they are running the same device, although that is much less likely if all of the same steps are followed.

Daydream is Google's VR providing and introduce with the Google's newest Pixel units. The Daydream platform is Google's own and the primary devices that are compatible are the Google Pixels and more lately to the Moto Z and Z force on Verizon which have already been updated to Android Nougat.

The method theoretically works with any device running on Android Nougat 7.0 or above. An LG V20 was also reportedly working just as well without any issues. Likewise, there may have been a Nexus 5 working with Daydream.With the openness of Android and the vast community of Android fans and developers, software can be manipulated to trick it into doing things it's not programmed to do from the factory. Any smartphone running Android Nougat should be able to support Daydream in theory, this isn't the actual case.

The most important question, How to try this on the smartphone.

The first thing user need to do is check wether the device is root access or not because it required to work, so if user don't have a rooted device, then they're still stucked without Daydream VR support.  For those who have rooted devices, the next step is to open up any file explorer application that will let you see and navigate through the folders that are only visible with root access. The file that users should be looking for is "/system/etc/permissions/handheld_core_hardware.xml" without the quotes, then add and /> lines into the root permission tagThe most important question, How to try this new on your smartphone.

After the modification of the file, all that is to be required is to reboot the phone to implement  the changes, after that you need to install the Daydream app as well as apps that were designed specifically for Daydream VR and utilize the Daydream View headset.