All cpreg read and write functions now return 0, so we can clean up
their prototypes:
* write functions return void
* read functions return the value rather than taking a pointer
to write the value to
This is a fairly mechanical change which makes only the bare
minimum set of changes to the callers of read and write functions.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
c4241c7d38