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/magnesium_defconfig b/configs/magnesium_defconfig
index 4969603..2fa6589 100644
--- a/configs/magnesium_defconfig
+++ b/configs/magnesium_defconfig
@@ -1,3 +1,3 @@
 CONFIG_ARM=y
 CONFIG_TARGET_MAGNESIUM=y
-CONFIG_CMD_NET=y
+# CONFIG_CMD_SETEXPR is not set