CUDA 10.2: missing drmP.h in RedHat 8 kernel 4.18.0

This is confusing me; I need to install 10.2 on RedHat 8 (kernel 4.18.0) because a 3rd party software uses that version. The installation fails on:

   In file included from /tmp/selfgz21250/NVIDIA-Linux-x86_64-440.33.01/kernel/nvidia-drm/nvidia-drm-drv.c:27:
   /tmp/selfgz21250/NVIDIA-Linux-x86_64-440.33.01/kernel/nvidia-drm/nvidia-drm-fb.h:30:10: fatal error: drm/drmP.h: No such file or directory
    #include <drm/drmP.h>
             ^~~~~~~~~~~~
   compilation terminated.

I find this error on Google for kernel 5.5, but that is not the case here. The files in the /usr/include/drm folder come from the kernel:

[root@vr-forces ~]# yum whatprovides /usr/include/drm/drm.h

Last metadata expiration check: 1:20:18 ago on Thu 20 Jan 2022 12:08:08 PM CET.
kernel-headers-4.18.0-305.el8.x86_64 : Header files for the Linux kernel for use by glibc
Repo        : @System
Matched from:
Filename    : /usr/include/drm/drm.h

kernel-headers-4.18.0-305.el8.x86_64 : Header files for the Linux kernel for use by glibc
Repo        : BaseOS
Matched from:
Filename    : /usr/include/drm/drm.h

But if I look for example here drm - include/drm - Linux source code (v4.18) - Bootlin
Then the drmP.h file should be present in de 4.18 header, and not the drm.h.

I’ve downloaded the CUDO 10.2 for RedHat, but it expects different files then there are in my kernel headers?

Addendum: it seems the drmP.h should be in the kernel-devel rpm, but it is not. I have the kernel-devel installed and searched through the actual rpm used to install my system, but drmP.h is not in it, drm.h is.

All evidence seem to suggest RedHat has backported the change from kernel 5.x that removed the drmP.h. Which means CUDA 10.2 no longer is installable on RedHat or CentOS 8.