iio: cros_ec: Trace EC sensors command

iio: cros_ec: Trace EC sensors command

For debugging, add tracing for EC_CMD_MOTION_SENSE_CMD command:
- decode the name of the subcommand
- provide internal information for the most common sub-commands:
  setting range, frequency, EC probing frequency, ...
- display return status.

When enabled, the tracing output is similar to:
/sys/kernel/debug/tracing # echo 1 > events/cros_ec/enable ; echo 1 > tracing_on ; cat trace_pipe | grep MOTIONSENSE_CMD_SENSOR_ODR
 SensorDeviceImp-814     [003] .....   686.176782: cros_ec_motion_host_cmd: MOTIONSENSE_CMD_SENSOR_ODR, id: 1, data: 200000, result: 4, return: 12500

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>
Link: https://patch.msgid.link/20250121232007.1020666-1-gwendal@chromium.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>