Make bench program buildable and update git submodules

Makefile

@@ -1,3 +1,10 @@
+# Git Submodules
+SUBMODULES = \
+	gbit 
+
+GIT_SUBMODULES := $(shell git submodule update --init $(SUBMODULES))
+
+# Flags
 CFLAGS = -std=gnu99 -O2 -Wall -Wextra
 LDFLAGS = -lm
 
@@ -50,9 +57,9 @@ $(OUT)/cpu_instrs.h: tests/cpu_instrs.gb tests/rom2h.c
 	$(Q)$(CC) -o $(OUT)/rom2h tests/rom2h.c
 	@$(OUT)/rom2h
 
-$(OUT)/bench: $(OUT)/cpu_instrs.h prof.h cpu.c bench.c gameboy.h
+$(OUT)/bench: gbit/lib/tester.c gbit/lib/ref_cpu.c gbit/lib/inputstate.c gbit/lib/disassembler.c
 	$(VECHO) "  CC+LD\t$@\n"
-	$(Q)$(CC) -DENABLE_LCD=0 -o $@ cpu.c bench.c
+	$(Q)$(CC) -DENABLE_LCD=0 -DDEBUG -o $@ cpu.c bench.c $^
 
 # Download Game Boy ROMs with full source
 download_rom: