drm/xe/gt: Synchronize GT reset with device unbind

drm/xe/gt: Synchronize GT reset with device unbind

When unbinding wait for any GT reset in progress to complete. Unbinding
will release the mmio mapping but mmio operations are performed during
GT reset causing Kernel panic.

Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Balasubramani Vivekanandan <balasubramani.vivekanandan@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patch.msgid.link/20251103123144.3231829-5-balasubramani.vivekanandan@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>