gpio: wcove: Use -ENOTSUPP consistently

The GPIO library expects the drivers to return -ENOTSUPP in some
cases and not using analogue POSIX code. Make the driver to follow
this.
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

drivers/gpio/gpio-wcove.c

@@ -104,7 +104,7 @@ static inline int to_reg(int gpio, enum ctrl_register type)
 	unsigned int reg = type == CTRL_IN ? GPIO_IN_CTRL_BASE : GPIO_OUT_CTRL_BASE;
 
 	if (gpio >= WCOVE_GPIO_NUM)
-		return -EOPNOTSUPP;
+		return -ENOTSUPP;
 
 	return reg + gpio;
 }