kernel: disable AMD/Radeon GPU (causes KALLSYMS overflow with GCC 15)
These drivers add ~2M symbols which overflows the KALLSYMS linker
pass on GCC 15. Disable until we find a workaround or upgrade kernel.
Intel i915 + simpledrm remain for wide Intel ThinkPad support.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>