arch-arm, mem-ruby, sim: Add missing overrides

Change-Id: I5ab18960bd61953e68777746426adb657818f825
Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28168
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

src/sim/kernel_workload.hh

@@ -98,7 +98,7 @@ class KernelWorkload : public Workload
     }
 
     bool
-    insertSymbol(Addr address, const std::string &symbol)
+    insertSymbol(Addr address, const std::string &symbol) override
     {
         return kernelSymtab->insert(address, symbol);
     }