`averageEncodeLatency` is in microseconds, but incorrectly documented as milliseconds

[fredemmott]

https://github.com/NVIDIA/nvapi/blob/7cb76fce2f52de818b3da497af646af1ec16ce27/nvapi.h#L4663

    NvU32             averageEncodeLatency;        //!< Moving average encode latency in milliseconds.

When using a VR streaming headset, this is reporting an active session with ~ 900 latency - it is very clear that I am not playing VR with nearly a second of latency.

Based on nvidia-smi, this field is incorrectly documented, and is actually microseconds, not milliseconds:

PS C:\Windows\System32\DriverStore\FileRepository\nvmdi.inf_amd64_fe5a9cae5c641286> .\nvidia-smi encodersessions
# GPU Session    Process   Codec       H       V Average     Average
    0      32      23520   H.265    1792    1856     305         869
    0      32      23520   H.265    1792    1856     266         918
    0      32      23520   H.265    1792    1856     298         982
    0      32      23520   H.265    1792    1856     307         939