We can actually read this back from the device but we use this when
registered using standard I2C board data registration so make sure
it's there for OF too.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Tested-by: Sylwester Nawrocki <s.nawrocki@samsung.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>