Add imx-firmware to rootfs

Required for bluetooth.

Change-Id: If5cf486be369ec929e38058714dbfdc1fd70b88a
diff --git a/rootfs.mk b/rootfs.mk
index 38df36f..924c9b5 100644
--- a/rootfs.mk
+++ b/rootfs.mk
@@ -17,6 +17,7 @@
 	imx-board-gadget \
 	imx-board-tools \
 	imx-board-wlan \
+	imx-firmware \
 	imx-gpu-viv \
 	imx-gst1.0-plugin \
 	imx-vpu-hantro \