add .gitreview configuration

Change-Id: I2bf183f46ca1cb62be982ddc32bd249bfdf1ca86
diff --git a/.gitreview b/.gitreview
new file mode 100644
index 0000000..787894f
--- /dev/null
+++ b/.gitreview
@@ -0,0 +1,3 @@
+[gerrit]
+host=gerrit.osmocom.org
+project=erlang/osmo_dia2gsup