ARM: orion/gpio: Get rid of unused first parameter in orion_gpio_init()

The OF node pointer is always NULL, get rid of unused parameter in
orion_gpio_init(). As a side effect it will allow to switch GPIO
library to the fwnode API, as well as in case of resurrecting it here
it should be fwnode_handle anyways.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>