qtmultimedia: Enable gstreamer support
qtmultimedia: Enable gstreamer support

This helps qt5everywheredemo to play sample videos

Signed-off-by: Khem Raj <729d64b6f67515e258459a5f6d20ec88b2caf8df@gmail.com>

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