Github #275 Generate versionned libraries

Github #275 Generate versionned libraries

 * Improved parsing of the ArmNN's version at compile time
 * Reading the version directly from the Version.hpp file, to
   make sure not to break any build made with a different
   build system than CMake (or Ninja)
 * The version macro is set in the Version.hpp just like before,
   so setting it from the command line is no longer necessary

!android-nn-driver:2126

Signed-off-by: Guillaume Gardet <guillaume.gardet@arm.com>
Signed-off-by: Matteo Martincigh <matteo.martincigh@arm.com>
Change-Id: I0820094607734d283ded030e4ded0ae6f5889c86