Add qt5-qtbase with OpenGL ES2 enabled

Created by: PureTryOut

Resolves #994 (moved).

Someone please test this on an actual device, as I could only test it in Qemu which worked fine without OpenGL ES2 as well. If this is confirmed working, we can upstream this pretty quickly to Alpine hopefully.

Note that qt5-qtdeclarative needed rebuilding, otherwise kwin wouldn't even launch.