drm/amdgpu: properly guard the generic discovery code

It's only available on navi and newer.
Reviewed-by: Xiaojie Yuan <xiaojie.yuan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -2615,7 +2615,7 @@ int amdgpu_device_init(struct amdgpu_device *adev,
 	if (amdgpu_mes && adev->asic_type >= CHIP_NAVI10)
 		adev->enable_mes = true;
 
-	if (amdgpu_discovery) {
+	if (amdgpu_discovery && adev->asic_type >= CHIP_NAVI10) {
 		r = amdgpu_discovery_init(adev);
 		if (r) {
 			dev_err(adev->dev, "amdgpu_discovery_init failed\n");
@@ -2885,7 +2885,7 @@ void amdgpu_device_fini(struct amdgpu_device *adev)
 	if (IS_ENABLED(CONFIG_PERF_EVENTS))
 		amdgpu_pmu_fini(adev);
 	amdgpu_debugfs_preempt_cleanup(adev);
-	if (amdgpu_discovery)
+	if (amdgpu_discovery && adev->asic_type >= CHIP_NAVI10)
 		amdgpu_discovery_fini(adev);
 }