Make sure sdio_bus device is powered up in order to probe device.

When adding a device, which has previously powered down the sdio bus,
it is not possible to insmod it again. As result the call to
mmc_power_restore_host(...) in function sdio_bus_probe() initializes
the host power/clocks for a new attempt to probe new devices.

Signed-off-by: Quallenauge <Hamsi2k@freenet.de>
Simple debug statement added to get informed the device is already powered off.