samples: sensor: vl53l0x: Update for SENSOR_CHAN_DISTANCE refactor

SENSOR_CHAN_DISTANCE is now in meters. Print value in meters, as
double, this requires printf() and CONFIG_STDOUT_CONSOLE. This is
similar to how other sensor samples have it.

Fixes: #5693

Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>