Add open-iscsi packages for Nova compute nodes.

Begin splitting packages into service-specific files, n-cpu and
n-vol are the first.

Change-Id: I3e7c412ff125dbadd18b59af55fb7dea9ea17b07
diff --git a/files/apts/n-vol b/files/apts/n-vol
new file mode 100644
index 0000000..edaee2c
--- /dev/null
+++ b/files/apts/n-vol
@@ -0,0 +1,3 @@
+iscsitarget  # NOPRIME
+iscsitarget-dkms  # NOPRIME
+lvm2