qt5multimedia: select Qt5OpenGL module in case OpenGL support is enabled

Qt5Multimedia needs Qt5OpenGL module in case OpenGL support is
enabled.

Fixes bug reported by Marco Trapanese ([1]).

[1] http://lists.busybox.net/pipermail/buildroot/2016-May/161288.html

Signed-off-by: Peter Seiderer <ps.report@gmx.net>
Acked-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/qt5/qt5multimedia/Config.in

@@ -3,6 +3,7 @@ config BR2_PACKAGE_QT5MULTIMEDIA
 	select BR2_PACKAGE_QT5BASE
 	select BR2_PACKAGE_QT5BASE_GUI
 	select BR2_PACKAGE_QT5BASE_NETWORK
+	select BR2_PACKAGE_QT5BASE_OPENGL_LIB if BR2_PACKAGE_QT5BASE_OPENGL
 	help
 	  Qt is a cross-platform application and UI framework for
 	  developers using C++.