Fix NPOT decoration texture binding

If the context does not support the NPOTTextureRepeat (i.e. GL_OES_texture_npot extension), wrapping must be set to CLAMP_TO_EDGE to prevent invalid texture mapping.

Change-Id: I3ededccc14a32188986529c14fa91161fb383cfc
Reviewed-by: Jørgen Lind <jorgen.lind@digia.com>
Reviewed-by: Laszlo Agocs <laszlo.agocs@digia.com>