Freescale Yocto release L3.14.52_1.1.0_ga comes with Qt5 recipes for version 5.5.0.
What files should I modify to safely build a lower version (say 5.2.x)?
If you want to change to Qt 5.2 I would recommend looking at the Qt image recipe and write a similar recipe with the equivalent Qt 5.2 packages. Unfortunately the BSPs do not hold on to older Qt recipes so there is not an easy out-of-the-box solution for this.
You may look at older BSPs, perhaps the L3.10.XX releases would better suit your needs and actually use Qt 5.2, if I recall correctly.
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