Remove support for End Of Life (EOL) Fedora 22

Fedora 22 reaches its EOL on 19-JUL-2016[1].  Remove it as
officially supported distribution.

The current two supported Fedora distributions are Fedora 23 and Fedora
24.  (Change Ia4a58de4973ef228735c48b33453a0562dc65258 already added
support for Fedora 24.)

[1] https://fedoramagazine.org/fedora-22-end-of-life-2016-july/

Change-Id: I5b4e1ddb6165a9065e80e84175246678a7356f18
diff --git a/files/rpms/nova b/files/rpms/nova
index 594393e..a883ec4 100644
--- a/files/rpms/nova
+++ b/files/rpms/nova
@@ -7,7 +7,7 @@
 genisoimage # required for config_drive
 iptables
 iputils
-kernel-modules # dist:f22,f23,f24
+kernel-modules # dist:f23,f24
 kpartx
 kvm # NOPRIME
 libvirt-bin # NOPRIME