make cbfs target recursive

Signed-off-by: Gao feng <feng@hyper.sh>

Makefile.am

@@ -2,3 +2,5 @@ SUBDIRS=src build
 
 initrd-local:
 	@echo finish make initrd
+cbfs-local:
+	@echo finish make cbfs

build/Makefile.am

@@ -8,6 +8,7 @@ initrd-local:
 else
 initrd-local:
 	bash ./make-initrd.sh
-cbfs:
-	bash ./make-initrd.sh cbfs
 endif
+
+cbfs-local:
+	bash ./make-initrd.sh cbfs

configure.ac

@@ -4,7 +4,7 @@
 AC_PREREQ([2.69])
 AC_INIT([hyperstart], [0.2], [www.hyper.sh])
 AM_INIT_AUTOMAKE([-Wall -Werror foreign subdir-objects])
-AM_EXTRA_RECURSIVE_TARGETS([initrd])
+AM_EXTRA_RECURSIVE_TARGETS([initrd cbfs])
 AC_CONFIG_SRCDIR([src/init.c])
 AC_CONFIG_HEADERS([config.h])