Enable build of mesa-demos for userland graphics drivers

[clopez]

Enable build of mesa-demos for userland graphics drivers

• mesa-demos can be built fine if both gles1 and egl options are disabled. This allows to have utilities like glxinfo or glxgears

[clopez]

,mm, this is going to fail to build if the wayland package option gets enabled (and it gets enabled if the distro has the feature) unless poky contains this patch that I just sent to the oe-core mailing list

I guess is better that we disable wayland here as well. On this package enabling packageconfig option wayland without egl is useless in the end.

[clopez]

Looks good. Thanks for this. The only request would be to keep the current git log format:

https://meta-raspberrypi.readthedocs.io/en/latest/contributing.html

Pushed a new commit with that format.

Thanks!