debian: Add sub-package for libosmo-gsup-client

Change-Id: Iad227bb477d64da30dd6bfbbe1bd0c0a55be9474
diff --git a/debian/libosmo-gsup-client-dev.install b/debian/libosmo-gsup-client-dev.install
new file mode 100644
index 0000000..8a75973
--- /dev/null
+++ b/debian/libosmo-gsup-client-dev.install
@@ -0,0 +1,5 @@
+usr/include/osmocom/gsupclient
+usr/lib/*/libosmo-gsup-client*.a
+usr/lib/*/libosmo-gsup-client*.so
+usr/lib/*/libosmo-gsup-client*.la
+usr/lib/*/pkgconfig/libosmo-gsup-client.pc