moves mmu related code into mmu unit

src/sysc/sc_core_adapter.h

@@ -146,10 +146,10 @@ public:
 
     void wait_until(uint64_t flags) override {
         SCCDEBUG(owner->hier_name()) << "Sleeping until interrupt";
+        PLAT::wait_until(flags);
         while(this->reg.pending_trap == 0 && (this->csr[iss::arch::mip] & this->csr[iss::arch::mie]) == 0) {
             sc_core::wait(wfi_evt);
         }
-        PLAT::wait_until(flags);
     }
 
     void local_irq(short id, bool value) override {