Add a configure option to disable glesv1 or glesv2
Because mesa can be built without glesv1 so it breaks autodetection.
Fixes: https://bugs.archlinux.org/task/64032 ('mesa-demos doesn't build, unable to find GLES/gl.h')
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Because mesa can be built without glesv1 so it breaks autodetection.
Fixes: https://bugs.archlinux.org/task/64032 ('mesa-demos doesn't build, unable to find GLES/gl.h')