While this is a common topic on CMake projects, I found that many many projects repeat the same code with the same objective.
I wanted to reduce CMakeLists.txt boilerplate code and created a PC file generator module that attempts to generate a pkg-config PC file automatically from a target definition.
It is quite basic but it may suit many projects.
The module can be found at GitHub - antoniovazquezblanco/cmake-pcfilegenerator: Automatically generate PC files for your CMake targets.