smc91c111: allow access to reserved register

Some drivers seems to access the reserved register in bank 0 so allow and
ignore these accesses.

Signed-off-by: Lars Munch <lars@segv.dk>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

hw/smc91c111.c

@@ -277,6 +277,8 @@ static void smc91c111_writeb(void *opaque, target_phys_addr_t offset,
         case 10: case 11: /* RPCR */
             /* Ignored */
             return;
+        case 12: case 13: /* Reserved */
+            return;
         }
         break;
 
@@ -463,6 +465,8 @@ static uint32_t smc91c111_readb(void *opaque, target_phys_addr_t offset)
         case 10: case 11: /* RPCR */
             /* Not implemented.  */
             return 0;
+        case 12: case 13: /* Reserved */
+            return 0;
         }
         break;