This field is used to decide whether data needs to be transferred back
to the host after a command is completed.
Previously, this was determined using the length field, and length was
cleared to 0 after a transfer was completed. However, length will be
used in future patches after a host to controller transfer completes, so
we need some other way to tell what kind of data transfer is required.
Change-Id: I6b27cf7816908394735fc95c15bd5eb40a7c0157
Signed-off-by: Daniel Verkamp <daniel.verkamp@intel.com>