PM / QoS: add dev_pm_qos_update_request_timeout()

Add dev_pm_qos_update_request_timeout() that works in the same way as
pm_qos_request_timeout().

Bug 1364240

Change-Id: I9da700df443f48099eac929055e9fe2db4c2f540
Signed-off-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-on: http://git-master/r/288808