4630 clean stale references to ddi_iopb_alloc and ddi_iopb_free
4634 undocument scsi_hba_attach() and ddi_dma_lim(9s)

@@ -76,12 +76,10 @@
                 pdip = (A_TO_TRAN(ap))->tran_hba_dip;
 
                 /*
                  * use i_ddi_mem_alloc() for now until we have an interface to
                  * allocate memory for DMA which doesn't require a DMA handle.
-                 * ddi_iopb_alloc() is obsolete and we want more flexibility in
-                 * controlling the DMA address constraints.
                  */
                 while (i_ddi_mem_alloc(pdip, &scsi_alloc_attr, datalen,
                     ((callback == SLEEP_FUNC) ? 1 : 0), 0, NULL,
                     &bp->b_un.b_addr, &rlen, NULL) != DDI_SUCCESS) {
                         if (callback == SLEEP_FUNC) {