drm/amdgpu: set ip specific ras interface pointer to NULL after free it

to prevent access to dangling pointers

Signed-off-by: Hawking Zhang <Hawking.Zhang@amd.com>
Reviewed-by: Tao Zhou <tao.zhou1@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
5 files changed