Get rid of usage of CMake module

The CMake apps module isn't required here, this isn't a binding
or nothing to do with the Application Framework. Usage of the CMake
module impl property and commands that we don't want to be handled by
it like a default install directory.

Change-Id: Iba68b9e6802320069fda2f5a563536b39900dd3c
Signed-off-by: Romain Forlot <romain.forlot@iot.bzh>