Add aiy-board-resize2fs to the root filesystem.

Change-Id: I016fb381b83a04aa20cd0953ea7a3808931a5d3b
diff --git a/rootfs.mk b/rootfs.mk
index 37dbc60..6b0dec9 100644
--- a/rootfs.mk
+++ b/rootfs.mk
@@ -28,6 +28,7 @@
 	aiy-board-audio \
 	aiy-board-gadget \
 	aiy-board-keyring \
+	aiy-board-resize2fs \
 	aiy-board-tools \
 	aiy-board-wlan \
 	bluetooth \