After ROCKCHIP_SPI_VER2_TYPE2, SR->STB is a more accurate judgment
bit for spi slave transmition.
Signed-off-by: NJon Lin <jon.lin@rock-chips.com>
Link: https://lore.kernel.org/r/20210621104800.19088-5-jon.lin@rock-chips.comSigned-off-by: NMark Brown <broonie@kernel.org>