spi: mpc52xx: fix use-after-free on registration failure

spi: mpc52xx: fix use-after-free on registration failure

Make sure to disable and free the interrupts in case controller
registration fails to avoid a potential use-after-free and resource
leak.

This issue was flagged by Sashiko when reviewing a controller
deregistration fix.

Fixes: 42bbb70980f3 ("powerpc/5200: Add mpc5200-spi (non-PSC) device driver")
Cc: stable@vger.kernel.org	# 2.6.33
Cc: Grant Likely <grant.likely@secretlab.ca>
Link: https://sashiko.dev/#/patchset/20260414134319.978196-1-johan%40kernel.org?part=3
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://patch.msgid.link/20260421125800.1537361-1-johan@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>