Legacy tests: Use find_package to find python exe
Legacy tests: Use find_package to find python exe

Legacy test cmakefile was finding python with find_program.
This does not work well on windows and a version can not be force.

Use the standard find_package instead.

Signed-off-by: Kevin Rocard <f6672397850e914591889d29dcaf9077eb1a8a4f@intel.com>

miguelgaio/parameter-framework,miguelgaio/parameter-framework,clero/parameter-framework,01org/parameter-framework,clero/parameter-framework,clero/parameter-framework,krocard/parameter-framework,dawagner/parameter-framework,krocard/parameter-framework,miguelgaio/parameter-framework,mgaio/parameter-framework,01org/parameter-framework,mgaio/parameter-framework,01org/parameter-framework,mgaio/parameter-framework,dawagner/parameter-framework,krocard/parameter-framework,dawagner/parameter-framework