wl18xx: wlan_irq: support platform dependent interrupt types
* Interrupt request need to happen when the wilink chip is powered on and
driving the wlan_irq line. This avoids spurious interrupt issues that
are a result of different external pulls configuration on different
platforms
* Allow working with wl18xx level-low and falling edge irqs by configuring
wl18xx to invert the device interrupt
Signed-off-by: Eyal Reizer <eyalr@ti.com> Signed-off-by: Kalle Valo <kvalo@codeaurora.org>