pinctrl: apple: add missing bits.h header

This is needed for the BIT(n) macro.
Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20211121165642.27883-5-joey.gouly@arm.comSigned-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/pinctrl-apple-gpio.c

@@ -11,6 +11,7 @@
  */
 
 #include <dt-bindings/pinctrl/apple.h>
+#include <linux/bits.h>
 #include <linux/gpio/driver.h>
 #include <linux/interrupt.h>
 #include <linux/irq.h>