power: qcom: Modify APM timeout value for msm8953

As per msm8953 design, APM state machine could take more
than 200us for mode switching. Increase SW timeout constraint
value to 500us.

Also, update the mask used to check APM switch status.

CRs-Fixed: 992695
Change-Id: Ie0f8733fb5b39172fb14547292cbd05689a50230
Signed-off-by: Tirupathi Reddy <tirupath@codeaurora.org>