asoc: bolero: update logic for va clk switch on bolero 2.1

On bolero 2.1, SVA switch is not retain at VA_CLK
when switch between handset and headset mic sva.
Update the clock release logic during swr power event.

Change-Id: I62b492dcbff4b4f3249d1a6b3b792690b5b5c27c
Signed-off-by: Meng Wang <mengw@codeaurora.org>