Provide a mechanism to access only part of a control through the cs_dsp
interface.
Signed-off-by: NCharles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20211117132300.1290-9-ckeepax@opensource.cirrus.comSigned-off-by: NMark Brown <broonie@kernel.org>