qtmultimedia: add QT environment variable for camera support

Signed-off-by: Mike Engel <Mike.Engel@digi.com>

meta-digi-dey/dynamic-layers/qt6-layer/NXP/recipes-qt/qt6/qtmultimedia_%.bbappend

@@ -4,3 +4,7 @@ if ls ${D}${libdir}/pkgconfig/Qt6*.pc >/dev/null 2>&1; then
 fi
 }
 
+pkg_postinst:${PN}:ccimx6() {
+        echo '# Use FSL gstreamer plugin video source' >> $D${sysconfdir}/profile.d/qt6.sh
+        echo 'export QT_GSTREAMER_CAMERABIN_VIDEOSRC="imxv4l2src"' >> $D${sysconfdir}/profile.d/qt6.sh
+}