1.Go to library directory of arm qt first.

cd qt-everywhere-opensource-src-4.8.6-arm/src/phonon

2.Here you can find that the true code is not in the directory by

phonon.pro

3.But you can build as well.

make

make install

4.Head and library files will be installed into the directory as you set while installing the qt library for arm.

5.If you qt creater used another qt library directory, it is ok as you can copy the phonon head and library files to there.