update Makefile.am

Include generated config.h so that USE_GLES macro can be imported and then source files can be compied with <GLES3/gl3.h> when USE_GLES  is set

src/libprojectM/NativePresetFactory/Makefile.am

@@ -6,4 +6,5 @@ libNativePresetFactory_la_SOURCES= \
   MilkdropCompatability.hpp NativePreset.hpp NativePresetFactory.hpp
 
 libNativePresetFactory_la_CPPFLAGS = ${my_CFLAGS} \
+  -include $(top_builddir)/config.h \
   -I$(top_srcdir)/src/libprojectM