spi: Fixes for v4.14

There are a bunch of device specific fixes (more than I'd like, I've
been lax sending these) plus one important core fix for the conversion
to use an IDR for bus number allocation which avoids issues with
collisions when some but not all of the buses in the system have a fixed
bus number specified.

The Armada changes are rather large, specificially "spi: armada-3700:
Fix padding when sending not 4-byte aligned data", but it's a storage
corruption issue and there's things like indentation changes which make
it look bigger than it really is.  It's been cooking in -next for quite
a while now and is part of the reason for the delay.
Merge remote-tracking branches 'spi/fix/armada', 'spi/fix/idr', 'spi/fix/qspi', 'spi/fix/stm32' and 'spi/fix/uapi' into spi-linus