Makefile: add dependencies which require ffversion.h

Without this ffversion.h could sometimes be built too late
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Makefile

@@ -112,7 +112,7 @@ endef
 
 $(foreach P,$(PROGS),$(eval $(call DOPROG,$(P:$(PROGSSUF)$(EXESUF)=))))
 
-ffprobe.o cmdutils.o : libavutil/ffversion.h
+ffprobe.o cmdutils.o libavcodec/utils.o libavformat/utils.o libavdevice/avdevice.o libavfilter/avfilter.o libavutil/utils.o libpostproc/postprocess.o libswresample/swresample.o libswscale/utils.o : libavutil/ffversion.h
 
 $(PROGS): %$(PROGSSUF)$(EXESUF): %$(PROGSSUF)_g$(EXESUF)
 	$(CP) $< $@