gcc-plugin/examples/Makefile.am: add LDFLAGS for CUDA and OpenCL

gcc-plugin/examples/Makefile.am

@@ -25,6 +25,7 @@ endif !NO_BLAS_LIB
 endif STARPU_USE_CPU
 
 AM_LDFLAGS = $(top_builddir)/src/libstarpu-@STARPU_EFFECTIVE_VERSION@.la
+AM_LDFLAGS += $(STARPU_CUDA_LDFLAGS) $(STARPU_OPENCL_LDFLAGS)
 
 AM_CPPFLAGS =						\
   -I$(top_srcdir)/include				\