drm/amdgpu: use ttm_resource_manager_debug

Instead of calling the debug operation directly.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211124124430.20859-10-christian.koenig@amd.com