Add chroot target

Author: gsingh93

Makefile

@@ -297,6 +297,10 @@ rootfs-unmount:
 	sudo umount /dev/nbd0
 	sudo qemu-nbd -d /dev/nbd0
 
+.PHONY: chroot
+chroot:
+	sudo chroot $(ROOTFS_DIR) /bin/sh
+
 .PHONY: rootfs_clean
 rootfs_clean:
 	$(SUDO) rm -rf $(ROOTFS_DIR)