net-eth, mipsel-*: Add new target use/net-eth/dhcp/timeout/$TIMEOUT

features.in/mipsel-bfk3/config.mk

-use/mipsel-bfk3: use/kernel use/tty/S0
+use/mipsel-bfk3: use/kernel use/tty/S0 use/net-eth/dhcp/timeout/20
 	@$(call add_feature)
 	@$(call set,KFLAVOURS,bfk3-def)
 	@$(call set,VM_FSTYPE,ext2)

features.in/mipsel-mitx/config.mk

-use/mipsel-mitx: use/kernel use/tty/S0
+use/mipsel-mitx: use/kernel use/tty/S0 use/net-eth/dhcp/timeout/20
 	@$(call add_feature)
 	@$(call set,KFLAVOURS,mitx-xpa)
 	@$(call add,THE_PACKAGES,alt-config-be-t)

features.in/net-eth/config.mk

@@ -16,6 +16,11 @@ use/net-eth/networkd: use/net/networkd
 # typical boilerplate
 use/net-eth/dhcp: use/net-eth use/net/dhcp
 	@$(call add,NET_ETH,eth0:dhcp)
+	@$(call try,NET_ETH_TIMEOUT,7)
+	@$(call xport,NET_ETH_TIMEOUT)
+
+use/net-eth/dhcp/timeout/%: use/net-eth/dhcp
+	@$(call set,NET_ETH_TIMEOUT,$*)
 
 use/net-eth/networkd-dhcp: use/net-eth/networkd
 	@$(call add,NET_ETH,eth0:dhcp)

features.in/net-eth/rootfs/image-scripts.d/50-net-eth

@@ -42,11 +42,7 @@ write_etcnet_iface() {
 	append=
 	case "$proto" in
 	dhcp)
-		if [ $GLOBAL_ARCH = mipsel ]; then
-			append="DHCP_TIMEOUT=20"
-		else
-			append="DHCP_TIMEOUT=7"
-		fi
+		append="DHCP_TIMEOUT=$GLOBAL_NET_ETH_TIMEOUT"
 		;;
 	static)
 		echo "$ipv4addr" > "$dir/ipv4address"