bus: fsl-mc: pause the MC firmware when unloading

Pause the MC firmware when unloading the driver so that it doesn't
crash in certain scenarios, such as kexec.

Signed-off-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Link: https://lore.kernel.org/r/20210715140718.8513-6-laurentiu.tudor@nxp.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>