Add a workaround for the Camlink colorspace bug

The issue is described in detail here
https://assortedhackery.com/patching-cam-link-to-play-nicer-on-linux/

However note that this is a pure software workaround, no firmware
modification is needed and it works with off-the-shelf camlinks

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "camlink_workaround"]
+	path = camlink_workaround
+	url = https://github.com/BELABOX/camlink.git

Makefile

@@ -1,8 +1,14 @@
 CFLAGS=`pkg-config gstreamer-1.0 gstreamer-app-1.0 srt --cflags` -O2 -Wall
-LDFLAGS=`pkg-config gstreamer-1.0 gstreamer-app-1.0 srt --libs`
+LDFLAGS=`pkg-config gstreamer-1.0 gstreamer-app-1.0 srt --libs` -ldl
 
-belacoder: belacoder.c
-	$(CC) $(CFLAGS) $< -o $@ $(LDFLAGS)
+all: submodule belacoder
+
+submodule:
+	git submodule init
+	git submodule update
+
+belacoder: belacoder.o camlink_workaround/camlink.o
+	$(CC) $(CFLAGS) $^ -o $@ $(LDFLAGS)
 
 clean:
-	rm -f belacoder
+	rm -f belacoder *.o camlink_workaround/*.o