drm/amdgpu: fix buffer funcs setting order on suspend

We need to disable this after the last eviction
call, but before we disable the SDMA IP.

Fixes: b7043800 ("drm/amdgpu: move buffer funcs setting up a level")
Link: https://lore.kernel.org/r/87edgv4x3i.fsf@vps.thesusis.net


Reviewed-by: Luben Tuikov <ltuikov89@gmail.com>
Tested-by: Phillip Susi <phill@thesusis.net>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: Phillip Susi <phill@thesusis.net>
Cc: Luben Tuikov <ltuikov89@gmail.com>