ppp: add config options to tune discovery timeout and attempts

Upstream PPP project has added in commit 8e77984 options to tune discovery
timeout and attempts in the rp-pppoe plugin.

Expose these options in the uci datamodel for pppoe:
	padi_attempts: Number of discovery attempts
	padi_timeout: Initial timeout for discovery packets in seconds

Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>

package/network/services/ppp/Makefile

@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 include $(INCLUDE_DIR)/kernel.mk
 
 PKG_NAME:=ppp
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 
 PKG_SOURCE_PROTO:=git
 PKG_SOURCE_URL:=https://github.com/paulusmack/ppp

package/network/services/ppp/files/ppp.sh

@@ -210,6 +210,9 @@ proto_pppoe_init_config() {
 	proto_config_add_string "ac"
 	proto_config_add_string "service"
 	proto_config_add_string "host_uniq"
+	proto_config_add_int "padi_attempts"
+	proto_config_add_int "padi_timeout"
+
 	lasterror=1
 }
 
@@ -227,12 +230,16 @@ proto_pppoe_setup() {
 	json_get_var ac ac
 	json_get_var service service
 	json_get_var host_uniq host_uniq
+	json_get_var padi_attempts padi_attempts
+	json_get_var padi_timeout padi_timeout
 
 	ppp_generic_setup "$config" \
 		plugin rp-pppoe.so \
 		${ac:+rp_pppoe_ac "$ac"} \
 		${service:+rp_pppoe_service "$service"} \
 		${host_uniq:+host-uniq "$host_uniq"} \
+		${padi_attempts:+pppoe-padi-attempts $padi_attempts} \
+		${padi_timeout:+pppoe-padi-timeout $padi_timeout} \
 		"nic-$iface"
 }