gpio: tegra: Add lockdep class

Add lockdep class in order to fix debug warnings that are coming from a
legit nested use of irq_set_irq_wake() by the Tegra GPIO driver.

 WARNING: possible recursive locking detected
 ...
  (irq_set_irq_wake) from (tegra_gpio_irq_set_wake)
  (tegra_gpio_irq_set_wake) from (irq_set_irq_wake)
  (irq_set_irq_wake) from (brcmf_sdiod_intr_register [brcmfmac])
 ...

Tested-by: Peter Geis <pgwipeout@gmail.com>
Reported-by: Peter Geis <pgwipeout@gmail.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Author: digetx

drivers/gpio/gpio-tegra.c

@@ -560,6 +560,9 @@ static const struct dev_pm_ops tegra_gpio_pm_ops = {
 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(tegra_gpio_suspend, tegra_gpio_resume)
 };
 
+static struct lock_class_key gpio_lock_class;
+static struct lock_class_key gpio_request_class;
+
 static int tegra_gpio_probe(struct platform_device *pdev)
 {
 	struct tegra_gpio_info *tgi;
@@ -661,6 +664,7 @@ static int tegra_gpio_probe(struct platform_device *pdev)
 		bank = &tgi->bank_info[GPIO_BANK(gpio)];
 
 		irq_set_chip_data(irq, bank);
+		irq_set_lockdep_class(irq, &gpio_lock_class, &gpio_request_class);
 		irq_set_chip_and_handler(irq, &tgi->ic, handle_simple_irq);
 	}