Add section/priority for source package

Change-Id: I32b7f145ab3faddfc250ee4d1eb51ebde45b8791
diff --git a/debian/control b/debian/control
index 798ea52..b15a64d 100644
--- a/debian/control
+++ b/debian/control
@@ -1,6 +1,8 @@
 Source: imx-firmware
 Maintainer: AIY Projects <support-aiyprojects@google.com>
 Build-Depends: debhelper
+Section: misc
+Priority: optional
 
 Package: imx-firmware
 Section: misc