commands: move CMD_IFUP to commands/Kconfig

* this places the command into the "Network commands"
  section of Kconfig
* while at it, improve Kconfig documention

Signed-off-by: Holger Schurig <holgerschurig@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

commands/Kconfig

@@ -1068,6 +1068,23 @@ config CMD_HOST
 
 	  Usage: host DESTINATION
 
+config NET_CMD_IFUP
+	bool
+	prompt "ifup"
+	help
+	  Bring up network interfaces based on config files.
+
+	  Usage: ifup [-af] [INTF]
+
+	  Each INTF must have a script /env/network/INTF that set the variables
+	  ip (to 'static' or 'dynamic'), ipaddr, netmask, gateway, serverip
+	  and/or ethaddr. A script /env/network/INTF-discover can contains for
+	  discovering the ethernet device, e.g. 'usb'.
+
+	  Options:
+	          -a      bring up all interfaces
+	          -f      Force. Configure even if ip already set
+
 config CMD_MIITOOL
 	tristate
 	depends on PHYLIB

net/Kconfig

@@ -22,11 +22,4 @@ config NET_IFUP
 	default y
 	bool
 
-config NET_CMD_IFUP
-	bool
-	prompt "ifup support"
-	help
-	  This enables the 'ifup' command which is used to bring up network
-	  interfaces based on config files under /env/network/<ethname>
-
 endif