Add work around for nvc0 device GDEV_NVIDIA_QUERY_MP_COUNT query

In the <= nvc0 device, we use GDEV_NVIDIA_QUERY_MP_COUNT query.
So reverting this[1] change when the target chipset is <= nvc0.

[1]: dc8546121f6d7a86d90f049f05b7f1a066e9b018