- Why I did it
Fix setting PSU led to 'green' or 'red' states.
Fix return False if unsupported color request.
Remove 'off' option for PSU led API since it is not supported in Mellanox.
- How I did it
Fix import missing information.
Return 'False' when unsupported led color is requested, preventing an exception.
- How to verify it
Try to set PSU LED to different status with Mellanox platform device.
Try to set PSU LED color to unsupported color with Mellanox platform device.
