qtwebengine: Configure Ninja to honor PARALLEL_MAKE
qtwebengine: Configure Ninja to honor PARALLEL_MAKE

Fixes #137

Signed-off-by: Kai Ruhnau <a424dd034215c1a04a8a9ee56de23d5c25a1dcc2@target-sg.com>

schnitzeltony/meta-qt5,meta-qt5/meta-qt5,schnitzeltony/meta-qt5,sapiippo/meta-qt5,sapiippo/meta-qt5,meta-qt5/meta-qt5