lsm: miscellaneous fixes for multi-stage adsp VA

Fix compilation warnings from multi-stage VA code changes.
Correct sound model param size value to avoid failure from
second stage sound model registration.

Change-Id: I7f589f0ddece167233b61236b3e5b6585927f62d
Signed-off-by: Dhananjay Kumar <dhakumar@codeaurora.org>