- Why I did it
The current low power mode setting implementation requests the user to set the port to admin down first before toggling LP mode, this is not backward compatible, now revert it to the old way so that the user can toggle the LP mode regardless of the port admin status.
- How I did it
Revert the recent changes related to LPM in PR #14130 and #16545
- How to verify it
Run all sfputil and SFP platform API related tests on all the Mellanox platforms.
Signed-off-by: Kebo Liu <kebol@nvidia.com>