buildroot

package/kodi-visualisation-shadertoy: needs libplatform

Fixes

Makefile:477: *** libplatform is in the dependency chain of
 kodi-visualisation-shadertoy that has added it to its _DEPENDENCIES
 variable without selecting it or depending on it from Config.in.

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