package/vlc: skins2 depends on qt5base

package/vlc: skins2 depends on qt5base

Fixes

configure: error: The skins2 module depends on the Qt interface. Without
it you will not be able to open any dialog box from the interface, which
makes the skins2 interface rather useless. Install the Qt development
package or alternatively you can also configure with: --disable-qt
--disable-skins2.

http://autobuild.buildroot.net/results/ddb/ddb1ab48adb9705c44ed3d6d800b6d01ad52ac8c/

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>