aligns riscv_hart_msu_vp with riscv_hart_m_p

src/iss/arch/riscv_hart_msu_vp.h

@@ -286,7 +286,7 @@ public:
         return m[mode];
     }
 
-    riscv_hart_msu_vp();
+    riscv_hart_msu_vp(feature_config cfg = feature_config{});
     virtual ~riscv_hart_msu_vp() = default;
 
     void reset(uint64_t address) override;