net: Add option CONFIG_BOOTP_MAY_FAIL

This is useful if you want to look for a DHCP server, but try some
other settings if not available.

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/README b/README
index 6919392..6e313ad 100644
--- a/README
+++ b/README
@@ -1592,10 +1592,17 @@
 		CONFIG_BOOTP_NTPSERVER
 		CONFIG_BOOTP_TIMEOFFSET
 		CONFIG_BOOTP_VENDOREX
+		CONFIG_BOOTP_MAY_FAIL
 
 		CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
 		environment variable, not the BOOTP server.
 
+		CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
+		after the configured retry count, the call will fail
+		instead of starting over.  This can be used to fail over
+		to Link-local IP address configuration if the DHCP server
+		is not available.
+
 		CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
 		serverip from a DHCP server, it is possible that more
 		than one DNS serverip is offered to the client.