gpio: em: Use dynamic allocation of GPIOs

Use dynamic allocation of GPIOs instead of looking at the gpio%u alias
in DT.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-em.c

@@ -330,12 +330,7 @@ static int em_gio_probe(struct platform_device *pdev)
 			goto err0;
 		}
 
-		ret = of_alias_get_id(pdev->dev.of_node, "gpio");
-		if (ret < 0) {
-			dev_err(&pdev->dev, "Couldn't get OF id\n");
-			goto err0;
-		}
-		pdata->gpio_base = ret * 32; /* 32 GPIOs per instance */
+		pdata->gpio_base = -1;
 	}
 
 	gpio_chip = &p->gpio_chip;