If shell UART backend was enabled and logger uart backend was
not explicitly disabled then both were used resulting in logs
being printed twice on terminal.
Patch modifies default state of log uart backend to depend on
state of shell uart backend.
Signed-off-by: Krzysztof Chruscinski <krzysztof.chruscinski@nordicsemi.no>
The shell subsystem, as it is today, depends on having a UART,
therefore let's add the dependency explicitly in its Kconfig
Fixes#10190
Signed-off-by: Alberto Escolar Piedras <alpi@oticon.com>