Ensure that reads on volatile registers will correctly delegate
to the bus specific read function.
Signed-off-by: NDimitris Papastamos <dp@opensource.wolfsonmicro.com>
Acked-by: NLiam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>