msm: board-msm7x27a: Increase Idle timeout

For 7x27a and 7x27, clocks are controlled by modem. To improve stability,
reduce number of interactions to modem to turn on and off GPU clocks.

Change-Id: I3fbf8873bcdde36d2477e82d8a39c756b838662a
Signed-off-by: Sudhakara Rao Tentu <srtentu@codeaurora.org>