Normally there are at least two sh_serial instances. Add device id to
trace messages to make it clear which instance they belong to
otherwise its not possible to tell which serial device is accessed.

Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <cc1f9ff9f4259ae799750e452f8871849c7a104c.1635541329.git.balaton@eik.bme.hu>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>