Add private CI for the RHEL distro

Resolves: RHELPLAN-155186

plan.fmf

@@ -0,0 +1,20 @@
+/public:
+    summary: Public (Fedora) beakerlib tests
+    discover:
+        how: fmf
+        url: https://src.fedoraproject.org/tests/zlib.git
+    execute:
+        how: tmt
+
+/private:
+    enabled: false
+    adjust:
+    - when: distro == rhel
+      enabled: true
+      because: private tests are accesible only within rhel pipline
+
+    discover:
+	how: fmf
+	url: https://pkgs.devel.redhat.com/cgit/tests/zlib.git
+    execute:
+	how: tmt

public.fmf

@@ -1,6 +0,0 @@
-summary: Public (Fedora) beakerlib tests
-discover:
-    how: fmf
-    url: https://src.fedoraproject.org/tests/zlib.git
-execute:
-    how: tmt