regulator: rc5t583: Drop useless header

The RC5T583 includes the legacy header <linux/gpio.h> for no
reason, drop the include.

Signed-off-by: Linus Walleij <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Mark Brown <[e-mail]>

drivers/regulator/rc5t583-regulator.c

···
 #include <linux/platform_device.h>
 #include <linux/regulator/driver.h>
 #include <linux/regulator/machine.h>
-#include <linux/gpio.h>
 #include <linux/mfd/rc5t583.h>
 
 struct rc5t583_regulator_info {