On the Raspberry Pi, use the Broadcom VideoCore GLES and EGL libs for kwin and kinfocenter

Upstream patches pending.
Unfortunately, this is what happens when things are installed in non-standard locations. I agree that this is not a good solution, but it's the only short-term one.
The proper solution is to use the paths provided by Qt5 in the build system. Currently, the affected packages re-implement finding GLES and EGL in a seperate CMake script, which they ship together with the sources. This is why we need to specify the paths all over again.
I'll push patches upstream for the next release of kwin and kinfocenter, but until they're accepted we'll have to live with the current solution.