Added flag in log_output module to add timestamp when message is
formatted to a string. Updated existing backends.
Signed-off-by: Krzysztof Chruscinski <krzysztof.chruscinski@nordicsemi.no>
Added flag in log_output module to add severity level when message is
formatted to a string. Updated existing backends.
Signed-off-by: Krzysztof Chruscinski <krzysztof.chruscinski@nordicsemi.no>