How to Remove Tampered from your Bootloader
This guide will help you remove the Tampered flag from your bootloader. In order to do this you MUST BE S-Off. If you are still S-On and would like to do this then you need to gain S-Off first. See my guide for gaining S-Off HERE.
There are few different way to do this. The easiest way is to use the Guru Bootloader Reset Tool. It is simply flashed in recovery. See HERE.
If you used revone to gain S-Off or still have an older hboot you can use this toolkit to remove the Tampered flag:
The generic method to reset the Tampered flag on any hboot regardless of how you gain S-off is outlined in this XDA thread: