spi/imx: select master mode for all channels

The hardware seems to have a race condition when the inactive
channels are in slave mode. We support master mode only, so
we can just switch all channels to master mode.

Signed-off-by: Sascha Hauer <[email protected]>
[ukleinek: add more verbose comment about the race]
Signed-off-by: Uwe Kleine-König <[email protected]>
Signed-off-by: Grant Likely <[email protected]>
1 file changed