drm/xe/xe_gt_debugfs: Add synchronous gt reset debugfs

We currently have debugfs support that allows the userspace to initiate
an asynchronous gt reset on command.  However, userspace may also wish
to wait for the completion of the gt reset before performing any
additional work.  To that end, add a version of the force_reset gt
debugfs function that operates synchronously.

Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/1068
Suggested-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
CC: John Harrison <john.c.harrison@intel.com>
CC: Stuart Summers <stuart.summers@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240605150828.2736396-1-jonathan.cavitt@intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>