[doc] Document undocumented structures

Undocumented structures cause warnings during documentation generation.

Add missing doxygen documentation comments for structures.
Signed-off-by: Simo Piiroinen <simo.piiroinen@jollamobile.com>

src/usb_moded-network.c

@@ -53,10 +53,15 @@
 #define UDHCP_CONFIG_LINK	"/etc/udhcpd.conf"
 
 const char default_interface[] = "usb0";
+
+/** IP forwarding configuration block */
 typedef struct ipforward_data
 {
+	/** Address of primary DNS */
 	char *dns1;
+	/** Address of secondary DNS */
 	char *dns2;
+	/** Interface from which packets should be forwarded */
 	char *nat_interface;
 }ipforward_data;
 

src/usb_moded-udev.c

@@ -50,8 +50,11 @@ static int cleanup = 0;
 static int cable = 0, charger = 0;
 static guint cable_connection_timeout_id = 0;
 
+/** Bookkeeping data for power supply locating heuristics */
 typedef struct power_device {
+        /** Device path used by udev */
         const char *syspath;
+        /** Likelyhood of being power supply */
         int score;
 } power_device;