Drop build option KWIN_BUILD_EGL
Review Request #124695 - Created Aug. 11, 2015 and submitted
It doesn't make much sense any more as we get EGL linked and included through epoxy anyway. Even more on Wayland it's just plain stupid to have EGL disabled. So removing the option just simplifies our code base without any disadvantages.
a) no idea how epoxy works, but it doesn't link any GL library itself here (it's an epoxy build time dependency, though)
b) fglrx doesn't support EGL - though rather irrelevant since EGL from MESA will just be installed (as qt5-base dependency already) and not used, afaics there actually is a way to build a GLX system only.