I got it. linux 4.8 is enough for enable 4.3 in stock. Sorry for bother you. I check time by time https://www.x.org/wiki/RadeonFeature/. it does not mention about all requirements for opengl 4.3. There is only llmv 3.8 as requirements. I saw Alex Deucher updates that wiki page. May be he will add next time linux 4.8 in footnotes. Thank you and whole team for pushing radeon driver forward!