power: supply: Ratelimit no data debug output

Reduce the amount of output this dev_dbg() statement emits into logs,
otherwise if system software polls the sysfs entry for data and keeps
getting -ENODATA, it could end up filling the logs up.

This does in fact make systemd journald choke, since during boot the
sysfs power supply entries are polled and if journald starts at the
same time, the journal is just being repeatedly filled up, and the
system stops on trying to start journald without booting any further.

Signed-off-by: Marek Vasut <marex@denx.de>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>