[IPV4] ipconfig: Fix regression in ip command line processing

The recent changes for ip command line processing fixed some problems
but unfortunately broke some common usage scenarios.  In current
2.6.24-rc6 the following command line results in no IP address
assignment, which is surely a regression:

 ip=10.0.2.15::10.0.2.2:255.255.255.0::eth0:off

Please find below a patch that works for all cases I can find.

Signed-off-by: Amos Waterland <apw@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/Documentation/nfsroot.txt b/Documentation/nfsroot.txt
index c86dd38..31b3291 100644
--- a/Documentation/nfsroot.txt
+++ b/Documentation/nfsroot.txt
@@ -145,6 +145,7 @@
 		this option.
 
                   off or none: don't use autoconfiguration
+				(do static IP assignment instead)
 		  on or any:   use any protocol available in the kernel
 			       (default)
 		  dhcp:        use DHCP