qede: fix crash in rmmod qede while automatic debug collection

A crash has been observed if rmmod is done while automatic debug
collection in progress. It is due to a race  condition between
both of them.

To fix stop the sp_task during unload to avoid running qede_sp_task
even if they are schedule during removal process.

Signed-off-by: Alok Prasad <palok@marvell.com>
Signed-off-by: Shai Malin <smalin@marvell.com>
Signed-off-by: Ariel Elior <aelior@marvell.com>
Signed-off-by: Prabhakar Kushwaha <pkushwaha@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>