configs: Re-sync with cmd/Kconfig

Update the config.h and defconfig files for the commands that 8e3c036
converted over to Kconfig

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/spear600_defconfig b/configs/spear600_defconfig
index fac6a3c..f0e041f 100644
--- a/configs/spear600_defconfig
+++ b/configs/spear600_defconfig
@@ -7,6 +7,7 @@
 CONFIG_CMD_I2C=y
 # CONFIG_CMD_SETEXPR is not set
 CONFIG_CMD_DHCP=y
+CONFIG_CMD_MII=y
 CONFIG_CMD_PING=y
 CONFIG_NETDEVICES=y
 CONFIG_ETH_DESIGNWARE=y