spi: spi-xcomm: Remove forced bus numbering

Now that all slave devices are registerd via devicetree we do not need to use
forced bus numbering anymore and can let the spi core assign a number for us.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Remove outdated drivers from staging/iio

All these drivers have newer version in the non-staging area of IIO.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Sync spi core to upstream

We have some by now unused changes in the spi core and spi bitbang driver.
Revert those changes to get closer to upstream again.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Remove duplicated iio Makefile entry

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Remove deferred_probe from device struct

This seems to have come from a merge that went wrong. In the upstream version
deferred_probe is in the device_private struct.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>