Make CPU HW requirement apply on non-s390x only

plans/build-gating.fmf

@@ -4,6 +4,11 @@
 
 summary: "Build/PR gating tests for binutils"
 
+provision:
+  hardware:
+    disk:
+      - size: ">= 60 GiB"
+
 # Adjust rules
 adjust+:
   - because: "Plan to be ran when executed locally, or executed by CI system to gate a build or PR."
@@ -36,12 +41,11 @@ adjust+:
           - dnf config-manager --set-enabled rhel-CRB
           - dnf config-manager --set-enabled rhel-buildroot
 
-provision:
-  - hardware:
-      disk:
-        - size: ">= 60 GiB"
-      cpu:
-        processors: ">= 8"
+  - when: arch != s390x
+    provision+:
+      hardware+:
+        cpu:
+          processors: ">= 8"
 
 /common:
     discover: