Define HAVE_AV_CONFIG_H only when building libraries

Originally committed as revision 22294 to svn://svn.ffmpeg.org/ffmpeg/trunk

common.mak

@@ -31,7 +31,7 @@ endif
 
 ALLFFLIBS = avcodec avdevice avfilter avformat avutil postproc swscale
 
-CPPFLAGS := -DHAVE_AV_CONFIG_H -I$(BUILD_ROOT_REL) -I$(SRC_PATH) $(CPPFLAGS)
+CPPFLAGS := -I$(BUILD_ROOT_REL) -I$(SRC_PATH) $(CPPFLAGS)
 CFLAGS   += $(ECFLAGS)
 
 %.o: %.c

subdir.mak

@@ -5,6 +5,8 @@ include $(SUBDIR)../common.mak
 LIBVERSION := $(lib$(NAME)_VERSION)
 LIBMAJOR   := $(lib$(NAME)_VERSION_MAJOR)
 
+$(OBJS): CPPFLAGS += -DHAVE_AV_CONFIG_H
+
 ifdef CONFIG_STATIC
 all: $(SUBDIR)$(LIBNAME)