rockchip: gpio: remove outdated/misleading comment

Remove a comment claiming that this driver only supports the RK3288,
as we also use it on the RK3368, RK3399 and (most likely) on other
variants.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Acked-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>

Version-changes: 2
- use the dev_read_addr_ptr function in rk_gpio.c

drivers/gpio/rk_gpio.c

@@ -103,7 +103,6 @@ static int rockchip_gpio_probe(struct udevice *dev)
 	char *end;
 	int ret;
 
-	/* This only supports RK3288 at present */
 	priv->regs = dev_read_addr_ptr(dev);
 	ret = uclass_first_device_err(UCLASS_PINCTRL, &priv->pinctrl);
 	if (ret)