drm/xe/display: Convert __xe_pin_fb_vma()

Convert __xe_pin_fb_vma() for exhaustive eviction
using xe_validation_guard().

v2:
- Avoid gotos from within xe_validation_guard(). (Matt Brost)
- Adapt to signature change of xe_validation_guard(). (Matt Brost)
- Use interruptible waiting, since xe_bo_migrate() already does that.

Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://lore.kernel.org/r/20250908101246.65025-8-thomas.hellstrom@linux.intel.com