Merge remote-tracking branches 'spi/topic/rspi', 'spi/topic/sc18is602',...

Merge remote-tracking branches 'spi/topic/rspi', 'spi/topic/sc18is602', 'spi/topic/sh-msiof', 'spi/topic/spidev-test' and 'spi/topic/st-ssc4' into spi-next