Opengl 4.1 on ATI 6470m

I have a HP-EliteBook-8460p with ATI 6470m. According to the hardware the card haes OpenGL 4.1 support. But in Ubuntu 16.04 I get

andre@andre-HP-EliteBook-8460p:~$ glxinfo | grep "OpenGL version"
OpenGL version string: 3.0 Mesa 12.1.0-devel (git-727a9b2 2016-06-25 xenial-oibaf-ppa)

I am using this ppa BTW

ppaibaf/graphics-drivers

under "About This Computer" it says under Graphics

Gallium 0.4 on AMD CAICOS (DRM 2.43.0 / 4.4.0-24-generic, LLVM 3.8.0)

I thought the mesa etc. had OpenGL 4.1 support now at least. Is there a way to get that with open source drivers on this card?