If there is only one monitor connected and it's rotated then
the drm buf will also be rotated. This only the case with AMD and
only when using one monitor!
To fix this, we perform color conversion with an opengl shader
which allows us to also rotate the texture.
VAAPI supports rotation but it's not implemented by AMD at least.
Performance seems to be the same as when using VAAPI, even when
GPU usage is 100%.
