Added missing makefile target to build micropython unix port

Makefile

@@ -45,18 +45,21 @@ check-esp-sdk:
 	fi
 
 
-.requirements.txt.installed: requirements.txt
+.requirements.txt.installed: requirements.txt $(MP_UNIX)
 	cat requirements.txt | xargs -n1 $(MP_UNIX) -m upip install -p $(MOD_DIR)
 	touch $@
 
 $(MOD_DIR)/%.py: src/%.py
 	ln -s $(shell realpath --relative-to $(MOD_DIR) $<) $@
 
+$(MP_UNIX):
+	make -C micropython/ports/unix
 
 frozen-libs: .requirements.txt.installed $(LIB_SYMLINKS)
 
 micropython: micropython/ports/esp8266/build/firmware-combined.bin
 
+
 micropython/ports/esp8266/build/firmware-combined.bin: check-and-reinit-micropython-submodules check-esp-sdk frozen-libs
 	$(MAKE) -C micropython/mpy-cross
 	( \