I've created an RPM and SRPM of the mpss 3.8.4 mpss-modules file to allow you to use your KNC Xeon Phi's on CentOS 7.5. The resulting files can be found here:
or simply install the RPM using
rpm -Uvh https://www.nikhef.nl/~janjust/mpss/mpss-modules-3.10.0-862.el7.x86_64-3.8.4-1.x86_64.rpm
This works fine on my CentOS 7.5 box, but of course, use at your own risk and rattle your local Intel rep for an official update.
share and enjoy,