gpio: drop broken to_gpio_irq_chip() helper

mainline inclusion
from mainline-5.0-rc1
commit eee3919c5f2949a8b7b1e9fa239d153be1538656
category: bugfix
bugzilla: 5548
CVE: NA

---------------------------

Drop the broken to_gpio_irq_chip() container_of() helper, which would
break the build for anyone who tries to use it.

Specifically, struct gpio_irq_chip only holds a pointer to a struct
irq_chip so using container_of() on an irq-chip pointer makes no sense.

Fixes: da80ff81 ("gpio: Move irqchip into struct gpio_irq_chip")
Cc: Thierry Reding <treding@nvidia.com>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NJohan Hovold <johan@kernel.org>
Reviewed-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NJason Yan <yanaijie@huawei.com>
Reviewed-by: Nzhengbin <zhengbin13@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

include/linux/gpio/driver.h

@@ -146,11 +146,6 @@ struct gpio_irq_chip {
 	 */
 	unsigned int first;
 };
-
-static inline struct gpio_irq_chip *to_gpio_irq_chip(struct irq_chip *chip)
-{
-	return container_of(chip, struct gpio_irq_chip, chip);
-}
 #endif
 
 /**