spi: mpc52xx: fix use-after-free on unbind

spi: mpc52xx: fix use-after-free on unbind

The state machine work is scheduled by the interrupt handler and
therefore needs to be cancelled after disabling interrupts to avoid a
potential use-after-free.

Fixes: 984836621aad ("spi: mpc52xx: Add cancel_work_sync before module remove")
Cc: stable@vger.kernel.org
Cc: Pei Xiao <xiaopei01@kylinos.cn>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://patch.msgid.link/20260414134319.978196-5-johan@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>