remoteproc: imx: Fix typo in "failed"

There are several places where "failed" is spelled incorrectly.

Fix them all.

Reviewed-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>