tizenrt: Update defconfig from TizenRT 2.0

Align to TizenRT's default iotjs config:

    TizenRT/build/configs/artik053/iotjs/defconfig

Just debug options are enabled for debug configuration.

Bug: jerryscript-project#1777
IoT.js-DCO-1.0-Signed-off-by: Philippe Coval p.coval@samsung.com