arm64:dts:seco: Fix line-names of D18 GPIO-Expander

The line-names have to be assigned to the GPIO-Expander and not the
I2C-Bus.

arch/arm64/boot/dts/seco/include/imx8mp-d18.dtsi

@@ -57,7 +57,7 @@ &uart4 {
 	/delete-node/ fsl,uart-has-rtscts;
 };
 
-&i2c3 {
+&pca6416 {
 	gpio-line-names = "GPIO0/CAM0_PWR#", "GPIO1/CAM1_PWR#", "GPIO2/CAM0_RST#", "GPIO3/CAM1_RST#", "GPIO6/TACHIN", "GPIO7", "LCD1_BKLT_EN", "LCD1_BKLT_EN",
  			  "GPIO4", "LCD1_BKLT_EN", "P1_2_WiFi_EN", "WIFI_DISABLE", "BT_IRQ", "WLAN_WAKE#", "SECO_CODE_7", "SECO_CODE_8";
 };