XHCI: set dcbaap

src/hulk/usb/xhci.d

@@ -424,7 +424,7 @@ struct XHCI
             device_context_index[1 + i] = addr;
         }
 
-        /* TODO: write dcbaap. */
+        m_operational_registers.dcbaap = cast(ulong)device_context_index;
         /* TODO: write cr_ctrl. */
         /+ TODO:
         m_operational_registers.config = m_capability_registers.hcs_params1 & 0xFu;