Revert "build: Remove redundant config.mak includes from subdirectory Makefiles."

This reverts commit a6213f3dce4006e0d47bd938e15832987d95efef.

libavcodec/Makefile

@@ -1,3 +1,5 @@
+include $(SUBDIR)../config.mak
+
 NAME = avcodec
 FFLIBS = avutil
 

libavdevice/Makefile

@@ -1,3 +1,5 @@
+include $(SUBDIR)../config.mak
+
 NAME    = avdevice
 FFLIBS  = avformat avcodec avutil
 

libavfilter/Makefile

@@ -1,3 +1,5 @@
+include $(SUBDIR)../config.mak
+
 NAME = avfilter
 FFLIBS = avutil
 FFLIBS-$(CONFIG_MOVIE_FILTER) += avformat avcodec

libavformat/Makefile

@@ -1,3 +1,5 @@
+include $(SUBDIR)../config.mak
+
 NAME = avformat
 FFLIBS = avcodec avutil
 

libavutil/Makefile

@@ -1,3 +1,5 @@
+include $(SUBDIR)../config.mak
+
 NAME = avutil
 
 HEADERS = adler32.h                                                     \

libpostproc/Makefile

@@ -1,3 +1,5 @@
+include $(SUBDIR)../config.mak
+
 NAME = postproc
 FFLIBS = avutil
 

libswscale/Makefile

@@ -1,3 +1,5 @@
+include $(SUBDIR)../config.mak
+
 NAME = swscale
 FFLIBS = avutil