Move defaults from config_cmd_default.h to Kconfig

This sets the default commands Kconfig to match
include/config_cmd_default.h commands in the common/Kconfig and removes
them from include/configs.

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
[trini: rastaban, am43xx_evm_usbhost_boot, am43xx_evm_ethboot updates]
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/rd6281a_defconfig b/configs/rd6281a_defconfig
index 1a9fcd3..8fe8594 100644
--- a/configs/rd6281a_defconfig
+++ b/configs/rd6281a_defconfig
@@ -1,4 +1,6 @@
 CONFIG_ARM=y
 CONFIG_KIRKWOOD=y
 CONFIG_TARGET_RD6281A=y
-CONFIG_CMD_NET=y
+# CONFIG_CMD_IMLS is not set
+# CONFIG_CMD_FLASH is not set
+# CONFIG_CMD_SETEXPR is not set