Revert unwanted MMIOInst diff in e7fbf32b38

This stopped unmapped addresses from faulting, instead giving back a
list of all Invalid entries, triggering the "Fetched insts not enough"
assertion in FetchStage's doDecode. Fixes rv64mi-p-access.

src_Core/RISCY_OOO/procs/lib/MMIOInst.bsv

@@ -77,13 +77,15 @@ module mkMMIOInst(MMIOInst);
 
     method InstFetchTarget getFetchTarget(Addr phyPc);
         let addr = getDataAlignedAddr(phyPc);
-        if(addr >= mainMemBaseAddr && (addr < mainMemBoundAddr) &&
-	   addr != toHostAddr && addr != fromHostAddr)
-	   begin
-	      return MainMem;
-           end
+        if (soc_map.m_is_IO_addr (phyPc)) begin
+            return IODevice;
+        end
+        else if(addr >= mainMemBaseAddr && (addr < mainMemBoundAddr) &&
+                addr != toHostAddr && addr != fromHostAddr) begin
+            return MainMem;
+        end
         else begin
-           return IODevice;
+            return Fault;
         end
     endmethod