Once and Each time, Boot images are injected with required drivers they must be uploaded or deployed to all Distribution points.
SCCM has more than one way of achieving things, it depends which way you are more comfortable to do.
To Deploy Boot Image, Open Configuration Manager Console.
Go to Software Library > Operating Systems > Boot Images
Right Click on Required Boot Image and Click Update Distribution Points
But if you are looking to update only certain Distribution points, then Click on Distribute Contents
On Content Destination, Click Add and Select Distribution Point
Select the Required Distribution points and Click Next to Continue
Click Next to Continue
Click Close to Finish
This completes Deploying Boot Images to Distributions Points.