Add more fedora-atomic mirror exclusions

We don't need things like efi configs or pxeboot configs or ISOs.
Exclude these items to further reduce the size of the fedora mirror.

Change-Id: I93003b2f48d79dae627026e2c7af748ea9a9e34d

playbooks/roles/mirror-update/files/fedora-mirror-update

@@ -96,6 +96,13 @@ $K5START rsync -rltDvz \
     --exclude="ppc64le/" \
     --exclude="images/*.raw.xz" \
     --exclude="images/*.box" \
+    --exclude="images/*.iso" \
+    --exclude="images/efiboot.img" \
+    --exclude="images/install.img" \
+    --exclude="iso/*.iso" \
+    --exclude="os/EFI/BOOT/" \
+    --exclude="pxeboot/" \
+    --exclude="isolinux/" \
     $MIRROR/ $BASE/atomic/
 
 # TODO(pabelanger): Validate rsync process