tx_st_done is required for checking the transmission status of SPI
channels with different fifo levels
Signed-off-by: NPadmavathi Venna <padma.v@samsung.com>
Acked-by: Jassi Brar <jassisinghbrar@gmail.com
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>