MLK-16804-04 driver: irqchip: Add IPI SW workaround for imx8mq

On i.MX8MQ, when the CPU core is in power down state,
the IPI can NOT wakeup the core anymore(ERR011171), so using the
external IRQ32 to wakeup the core in power down idle
state successfully.

Signed-off-by: Bai Ping <ping.bai@nxp.com>
Reviewed-by: Anson Huang <anson.huang@nxp.com>
(cherry picked from commit d3244056)