logging: Default to IMMEDIATE mode for native targets

Instead of having the boards override the default
in their Kconfig.defconfig
let's just default to IMMEDIATE logging mode in the main
definition if we are building for a ARCH POSIX board.

This avoid issues w dependencies being lost if not duplicated
correctly.

Signed-off-by: Alberto Escolar Piedras <alberto.escolar.piedras@nordicsemi.no>
4 files changed