UMI Stream Should return DEVERR for READ_REQ larger than DW.

UMI Stream Module only supports reads less than or equal to DW. Could be nice to support larger than DW reads. I think it would make sense to return DEVERR for READ_REQ larger than DW if it is not going to be supported. [umi spec DEVERR](https://github.com/zeroasiccorp/umi/blob/e57520f597e0205fdd347d5dc57ef7e9a4b176f7/README.md?plain=1#L276)