mesa-grate needs to be removed (affects ouya-ouya, samsung-i927, samsung-p4wifi)

mesa-grate is a mesa fork, which still requires the python2 package py2-mako to build. Since python2 is getting dropped from Alpine, and that package doesn't exist anymore, we can't keep mesa-grate around anymore. I was told, that the patches from this fork did not make it into mainline mesa unfortunately... so we're just going to switch the three devices to mesa-dri-swrast.

Commit where mesa-grate did still exist: 1573a806