xmlGenerator use provided separator instead of space
xmlGenerator use provided separator instead of space

PFWScriptGenerator was incorrectly using space to
separate parameter path for the `setElementSequence`
command.

Use the provided separator.

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

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