ssb: gpio: Use generic_handle_irq_safe()

On PREEMPT_RT enabled kernels the demultiplex interrupt handler is force
threaded and runs with interrupts enabled. The invocation of
generic_handle_domain_irq() with interrupts enabled triggers a lockdep
warning due to a non-irq safe lock acquisition.

Instead of disabling interrupts on the driver level, use
generic_handle_domain_irq_safe().

[ tglx: Split out from combo patch ]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/YnkfWFzvusFFktSt@linutronix.de

drivers/ssb/driver_gpio.c

@@ -132,7 +132,8 @@ static irqreturn_t ssb_gpio_irq_chipco_handler(int irq, void *dev_id)
 		return IRQ_NONE;
 
 	for_each_set_bit(gpio, &irqs, bus->gpio.ngpio)
-		generic_handle_irq(ssb_gpio_to_irq(&bus->gpio, gpio));
+		generic_handle_domain_irq_safe(bus->irq_domain, gpio);
+
 	ssb_chipco_gpio_polarity(chipco, irqs, val & irqs);
 
 	return IRQ_HANDLED;
@@ -330,7 +331,8 @@ static irqreturn_t ssb_gpio_irq_extif_handler(int irq, void *dev_id)
 		return IRQ_NONE;
 
 	for_each_set_bit(gpio, &irqs, bus->gpio.ngpio)
-		generic_handle_irq(ssb_gpio_to_irq(&bus->gpio, gpio));
+		generic_handle_domain_irq_safe(bus->irq_domain, gpio);
+
 	ssb_extif_gpio_polarity(extif, irqs, val & irqs);
 
 	return IRQ_HANDLED;