gpio: da8xx_gpio: Fix gpio name with address

The GPIO bank numbers do not appear in the device tree,
so make the gpio name based on the address
(ie gpio@42110000_25 vs 25)

Signed-off-by: chao zeng <chao.zeng@siemens.com>
diff --git a/drivers/gpio/da8xx_gpio.c b/drivers/gpio/da8xx_gpio.c
index d106e98..b310f2d 100644
--- a/drivers/gpio/da8xx_gpio.c
+++ b/drivers/gpio/da8xx_gpio.c
@@ -545,12 +545,20 @@
 {
 	struct davinci_gpio_plat *plat = dev_get_plat(dev);
 	fdt_addr_t addr;
+	char name[18], *str;
 
 	addr = dev_read_addr(dev);
 	if (addr == FDT_ADDR_T_NONE)
 		return -EINVAL;
 
 	plat->base = addr;
+
+	sprintf(name, "gpio@%4x_", (unsigned int)plat->base);
+	str = strdup(name);
+	if (!str)
+		return -ENOMEM;
+	plat->port_name = str;
+
 	return 0;
 }