spi: Fixes for v4.7

A few small driver-specific fixes for SPI, all in the normal important
if you hit them category especially the rockchip driver fix which
addresses a race which has been exposed more frequently with some recent
performance improvements.
Merge remote-tracking branches 'spi/fix/ep93xx', 'spi/fix/rockchip', 'spi/fix/sunxi' and 'spi/fix/ti-qspi' into spi-linus