TSE MAC and Marvell 88E1111

Try to use a separate descriptor for the "next" argument in alt_avalon_sgdma_construct_mem_to_stream_desc.

        alt_avalon_sgdma_construct_mem_to_stream_desc(
           (alt_sgdma_descriptor *) desc, // descriptor I want to work with
           ((alt_sgdma_descriptor *) desc)+1,// pointer to "next"
           (alt_u32 *)ActualData,               // starting read address
           (length),                                  //#  bytes
           1,                                        // don't read from constant address
           1,                                        // generate sop
           1,                                        // generate endofpacket signal
           0);                                       // atlantic channel (don't know/don't care: set to 0)