arch endian ties with cfg.bigendian

```
[0x00000000]> e cfg.bigendian
false
[0x00000000]> e arch.endian
little
[0x00000000]> e arch.endian =big
[0x00000000]> e cfg.bigendian
false
[0x00000000]>
```

last false should be true , and same goes the other way around imho