Release the parent interrupt request during runtime suspend, allowing
the parent interrupt controller to enter runtime suspend if there are
no active users.

This change may not have a visible impact if the parent controller is
the GIC, but it can enable significant power savings for parent IRQ
controllers like IRQSteer inside a subsystem on i.MX8 SoCs. Releasing
the parent IRQ provides an opportunity for the subsystem to enter suspend
states if there are no active users.
Signed-off-by: Shenwei Wang <shenwei.wang@nxp.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>