Fix license headers in Qml grammar specification

The grammar file itself wasn't updated accordignly and the license headers that
are embedded in the grammar that will be copied into the generated files were
also oudated. Re-generating the parser would produce files with the wrong
license headers.

Change-Id: I1db83df8a9c4bddfb58901f41a4d40f6b1396507
Reviewed-by: Lars Knoll <lars.knoll@digia.com>