audio-hal: soft step volume params controls

set/get soft step volume control params values dynamically
for each usecase. each usecase can set different params values.
these values are set to module through mixer command.

Change-Id: I8ae200046ca5ab1ce253fc43e241d794fbb52183
Signed-off-by: Krishna Kishor Jha <quic_kkishorj@quicinc.com>