soc_widget_read API returns the register data and it is possible
that a register can contain 0xffffffff. Thus, change the prototype
of soc_widget_read to return only the error code and pass the reg
data through pointer argument.
Signed-off-by: NArun Shamanna Lakshmi <aruns@nvidia.com>
Signed-off-by: NMark Brown <broonie@linaro.org>