qos: Don't disable interrupts while holding pm_qos_lock

None of the pm_qos functions actually run in interrupt context; if some
driver calls pm_qos_update_target in interrupt context then it's already
broken. There's no need to disable interrupts while holding pm_qos_lock,
so don't do it.

Change-Id: I18b2bf6ec36d93259f69e652268f57e61fde275c
Signed-off-by: Sultan Alsawaf <sultan@kerneltoast.com>