Fix dstat dependencies for memory_tracker on SUSE

Memory_tracker imports psutil, but does not run inside a pip/virtualenv
so the system provided psutil library needs to be provided. This
is matching what is done for other non-SUSE distributions

Change-Id: I96f944730dc8644333d906d71339351b29b03e08
diff --git a/files/rpms-suse/dstat b/files/rpms-suse/dstat
index 2b643b8..0d9da44 100644
--- a/files/rpms-suse/dstat
+++ b/files/rpms-suse/dstat
@@ -1 +1,2 @@
 dstat
+python-psutil