ASoC: wcd9335: Add support to enable low power mode on codec

Codec is in digital core power collapse when there is no
audio usecase but low power audio usecases needs codec to
be out of power collapse. Changes bring codec out of
digital core power collapse for low power audio usecases
without enabling master clock.

CRs-fixed: 1022917
Change-Id: I762fc1dc6b6527608e73ac5144215ee141570aac
Signed-off-by: Sudheer Papothi <spapothi@codeaurora.org>
Signed-off-by: Vidyakumar Athota <vathota@codeaurora.org>