drm/amdgpu: Disable PCIe dynamic speed switching on Ryzen Pinnacle Ridge

drm/amdgpu: Disable PCIe dynamic speed switching on Ryzen Pinnacle Ridge

AMD Ryzen Pinnacle Ridge (Zen+, family 0x17 model 0x08) CPUs have
PCI controllers that don't support PCIe dynamic speed switching,
causing system freezes during GPU initialization when enabled.

Disable dynamic speed switching when this CPU is detected.

Assisted-by: Claude:sonnet
Fixes: 466a7d115326 ("drm/amd: Use the first non-dGPU PCI device for BW limits")
Closes: https://gitlab.freedesktop.org/drm/amd/-/work_items/5436
Reviewed-by: Lijo Lazar <lijo.lazar@amd.com>
Link: https://patch.msgid.link/20260709031520.841611-1-mario.limonciello@amd.com
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 9ceb4e034a327a04155f32f1cd1a5031dfa5fe02)
Cc: stable@vger.kernel.org