build: Update version to 0.2.0

Since 0.1.0, libavtp had some nice improvements:

 - cmoka is now a test dependency only
 - Fixed issues with gcc 9
 - RVF support.

So it makes sense to bump the version.

Signed-off-by: Ederson de Souza <ederson.desouza@intel.com>

build: Update version to MAJOR.MINOR.PATCH format

In meson.build, we have the 'version' argument from project() in the
format MAJOR.MINOR. This patch changes it so it explicitly shows the
PATCH version, following the format MAJOR.MINOR.PATCH.

Signed-off-by: Andre Guedes <andre.guedes@intel.com>