ipq40xx: fix NBG6617 LED mapping

The NBG6617's LEDs are wrongly identified in the 01_leds boardinit
script (board instead of boardname), resulting in referencing
non-existent LEDs in UCI.

Signed-off-by: David Bauer <mail@david-bauer.net>

target/linux/ipq40xx/base-files/etc/board.d/01_leds

@@ -35,9 +35,9 @@ meraki,mr33)
 	ucidef_set_interface_lan "eth0"
 	;;
 zyxel,nbg6617)
-	ucidef_set_led_wlan "wlan2g" "WLAN2G" "$board:green:wlan2G" "phy0tpt"
-	ucidef_set_led_wlan "wlan5g" "WLAN5G" "$board:green:wlan5G" "phy1tpt"
-	ucidef_set_led_usbport "usb" "USB" "${board}:green:usb" "usb1-port1" "usb2-port1" "usb3-port1" "usb4-port1"
+	ucidef_set_led_wlan "wlan2g" "WLAN2G" "${boardname}:green:wlan2G" "phy0tpt"
+	ucidef_set_led_wlan "wlan5g" "WLAN5G" "${boardname}:green:wlan5G" "phy1tpt"
+	ucidef_set_led_usbport "usb" "USB" "${boardname}:green:usb" "usb1-port1" "usb2-port1" "usb3-port1" "usb4-port1"
 	;;
 zyxel,wre6606)
 	ucidef_set_led_wlan "wlan2g" "WLAN2G" "${boardname}:green:wlan2g" "phy0tpt"