fix make handling

Fix the recurisve make targets by using $(MAKE).  Otherwise we get lots of
warnings and issues with parallel builds.

Fix the install target -- the man subdir was missing a dummy target.

Add proper .PHONY markings.

Change-Id: I640d42af0bdf96baf6ff0ca022fd3f7f444b2d05
Signed-off-by: Mike Frysinger <vapier@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/179621

Reviewed-by: Grant Grundler <grundler@chromium.org>
Signed-off-by: Chris Ball <chris@printf.net>

Makefile

@@ -34,15 +34,17 @@ mmc: $(objects)
 	$(CC) $(CFLAGS) -o $@ $(objects) $(LDFLAGS) $(LIBS)
 
 manpages:
-	cd man && make
+	$(MAKE) -C man
 
 install-man:
-	cd man && make install
+	$(MAKE) -C man install
 
 clean:
 	rm -f $(progs) $(objects)
-	cd man && make clean
+	$(MAKE) -C man clean
 
 install: $(progs) install-man
 	$(INSTALL) -m755 -d $(DESTDIR)$(bindir)
 	$(INSTALL) $(progs) $(DESTDIR)$(bindir)
+
+.PHONY: all clean install manpages install-man

man/Makefile

 all: 
 clean: 
+install:
+
+.PHONY: all clean install