drm/amd: Fix hang on amdgpu unload by using pci_dev_is_disconnected()

The commit 6a23e7b ("drm/amd: Clean up kfd node on surprise
disconnect") introduced early KFD cleanup when drm_dev_is_unplugged()
returns true. However, this causes hangs during normal module unload
(rmmod amdgpu).

The issue occurs because drm_dev_unplug() is called in amdgpu_pci_remove()
for all removal scenarios, not just surprise disconnects. This was done
intentionally in commit 39934d3 ("Revert "drm/amdgpu: TA unload
messages are not actually sent to psp when amdgpu is uninstalled"") to
fix IGT PCI software unplug test failures. As a result,
drm_dev_is_unplugged() returns true even during normal module unload,
triggering the early KFD cleanup inappropriately.

The correct check should distinguish between:
- Actual surprise disconnect (eGPU unplugged): pci_dev_is_disconnected()
  returns true
- Normal module unload (rmmod): pci_dev_is_disconnected() returns false

Replace drm_dev_is_unplugged() with pci_dev_is_disconnected() to ensure
the early cleanup only happens during true hardware disconnect events.

Cc: stable@vger.kernel.org
Reported-by: Cal Peake <cp@absolutedigital.net>
Closes: https://lore.kernel.org/all/b0c22deb-c0fa-3343-33cf-fd9a77d7db99@absolutedigital.net/
Fixes: 6a23e7b ("drm/amd: Clean up kfd node on surprise disconnect")
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Author: superm1

drivers/gpu/drm/amd/amdgpu/amdgpu_device.c

@@ -4924,7 +4924,7 @@ void amdgpu_device_fini_hw(struct amdgpu_device *adev)
 	 * before ip_fini_early to prevent kfd locking refcount issues by calling
 	 * amdgpu_amdkfd_suspend()
 	 */
-	if (drm_dev_is_unplugged(adev_to_drm(adev)))
+	if (pci_dev_is_disconnected(adev->pdev))
 		amdgpu_amdkfd_device_fini_sw(adev);
 
 	amdgpu_device_ip_fini_early(adev);
@@ -4936,7 +4936,7 @@ void amdgpu_device_fini_hw(struct amdgpu_device *adev)
 
 	amdgpu_gart_dummy_page_fini(adev);
 
-	if (drm_dev_is_unplugged(adev_to_drm(adev)))
+	if (pci_dev_is_disconnected(adev->pdev))
 		amdgpu_device_unmap_mmio(adev);
 
 }