ARM: qcom: disable power collapse when camera is working

To avoid CPU goes into power collapse mode,
set PM QOS latency to 100 when opening camera,
and reset it to -1 when closing camera.

Change-Id: If1e961a6133439f15cbd426d0d4600edfc4edace
Signed-off-by: Zhaohong Chen <zhaohong@codeaurora.org>