m7spr: use libril from sources

Change-Id: I0e3f23102a16c30b477dc08684e70d9ad5dc7409
diff --git a/device-proprietary-files.txt b/device-proprietary-files.txt
index 5123664..8b13789 100644
--- a/device-proprietary-files.txt
+++ b/device-proprietary-files.txt
@@ -1 +1 @@
-system/lib/libril.so
+