RISC-V: [drm] Display Core failed to initialize with v3.2.266!

[Heinrich Schuchardt]

On a riscv64 Unmatched board GPU output fails for a Radeon RX 6400:

[ +0.000917] [drm] Display Core failed to initialize with v3.2.266!
[ +0.000024] Unable to handle kernel access to user memory without uaccess routines at virtual address 0000000000000008

A Radeon R230 works fine but that is using another firmware driver.

ProblemType: Bug
DistroRelease: Ubuntu 24.04
Package: linux-image-6.8.0-20-generic 6.8.0-20.20.1
ProcVersionSignature: Ubuntu 6.8.0-20.20.1-generic 6.8.1
Uname: Linux 6.8.0-20-generic riscv64
ApportVersion: 2.28.0-0ubuntu1
Architecture: riscv64
CasperMD5json:
 {
   "result": "skip"
 }
Date: Fri Apr 19 13:00:35 2024
InstallationDate: Installed on 2024-04-18 (1 days ago)
InstallationMedia: Ubuntu-Server 24.04 LTS "Noble Numbat" - Beta riscv64 (20240418)
SourcePackage: linux-riscv
UpgradeStatus: No upgrade log present (probably fresh install)