drm/i915: Fix PXP cleanup missing from probe error rewind

Commit f67986b0 ("drm/i915/pxp: Promote pxp subsystem to top-level
of i915") added PXP initialization to driver probe path, but didn't add a
respective PXP cleanup on probe error.  That lack of cleanup seems
harmless as long as PXP is still unused and idle when a probe failure
occurs and error rewind path is entered, but as soon as PXP starts
consuming device and driver resources keeping them busy, kernel warnings
may be triggered when cleaning up resources provided by memory regions,
GGTT, GEM and/or VMA cache from the probe error rewind and/or module
unload paths because of missing PXP cleanup.  That scenario was observed
on attempts to fail the probe and enter the rewind path on injection of
now ignored error in device registration path.

Fix it.

Cc: Alan Previn <alan.previn.teres.alexis@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: Janusz Krzysztofik <janusz.krzysztofik@linux.intel.com>
Reviewed-by: Krzysztof Niemiec <krzysztof.niemiec@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250314205202.809563-7-janusz.krzysztofik@linux.intel.com