- Add a rev attribute to identify various McSPI IP version.
- Add a dev_attr structure to provide the number of chipselect
  supported by the instance.
Signed-off-by: Benoit Cousson <b-cousson@ti.com>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Govindraj.R <govindraj.raja@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>