Draft: mesa-grate, grate-drivers: new aports

mesa-grate provides basic OpenGL 1.4 support.

grate-drivers is a way to unify device packages having common dependencies and configs in one place.

I have put grate-drivers package into device/testing/ because it is like soc-* packages, i just can't name it soc-nvidia-tegra as it is not applicable for Tegra K1 (Tegra124) and newer chips, so we need a less common name.

Currently is draft because causes segfault when starting xorg