I installed PCL using the following commands.
sudo add-apt-repository ppa:v-launchpad-jochen-sprickerhof-de/pcl
sudo apt-get update
sudo apt-get install libpcl-a
you should specify the PCL dir for the CMake to find it.
In a terminal run :
$ locate PCLConfig.cmake
Then, add the found folder (without the filename) to your CMakeLists like the following :
set(PCL_DIR "/found/folder/")
#change X.x to whatever version yo installed
Sidenote : /usr/share/pcl-x.x is the usual path to your pcl folder.