The CSPI controller has only one clock, but the driver spi-imx.c needs
clock "per" to calculate bitrate divisor.
Signed-off-by: NJonas Andersson <jonas@microbit.se>
Acked-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>