lantiq: xway: rename nas0/ptm0 to dsl0

This change makes it possible to configure the wan/dsl ppp interface
settings independantly from the used TC-Layer (ATM/PTM).

By using dsl0 as interface name as for the xrx200 we can get rid of a
few conditionals which were introduced because of the different default
TC-Layer in xway and xrx200.

Signed-off-by: Mathias Kresin <dev@kresin.me>

target/linux/lantiq/base-files/etc/board.d/02_network

@@ -18,7 +18,7 @@ encaps="llc"
 payload="bridged"
 lan_mac=""
 wan_mac=""
-interface_wan=""
+interface_wan="dsl0"
 
 board=$(board_name)
 
@@ -230,10 +230,8 @@ ls /lib/modules/$(uname -r)/ltq_atm* 1> /dev/null 2>&1 && \
 	ucidef_add_atm_bridge "$vpi" "$vci" "$encaps" "$payload"
 
 if lantiq_is_vdsl_system; then
-	interface_wan="dsl0"
 	ucidef_add_vdsl_modem "$annex" "$tone" "$xfer_mode"
 else
-	interface_wan="nas0"
 	ucidef_add_adsl_modem "$annex" "/lib/firmware/adsl.bin"
 fi