ppc4xx: Kilauea: Add CONFIG_BOOTP_SUBNETMASK to Kilauea board config

When using dhcp/bootp the "netmask" environment variable is not set
because CONFIG_BOOTP_SUBNETMASK is not defined. But usually this is
desireable, so the following patch adds this this option to the board
config.

Signed-off-by: Markus Klotzbuecher <mk@denx.de>
Signed-off-by: Stefan Roese <sr@denx.de>

include/configs/kilauea.h

@@ -292,6 +292,7 @@
 #define CONFIG_BOOTP_BOOTPATH
 #define CONFIG_BOOTP_GATEWAY
 #define CONFIG_BOOTP_HOSTNAME
+#define CONFIG_BOOTP_SUBNETMASK
 
 /*
  * Command line configuration.