ASoC: cs35l35: Add DT handling for Inductor

Need to specify the inductor size in nH. This is a required property.

Signed-off-by: Brian Austin <brian.austin@cirrus.com>
Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@kernel.org>