drm/xe: Fix taking invalid lock on wedge

In the Linux kernel, the following vulnerability has been resolved:

drm/xe: Fix taking invalid lock on wedge

If device wedges on e.g. GuC upload, the submission is not yet enabled

and the state is not even initialized. Protect the wedge call so it does

nothing in this case. It fixes the following splat:

[] xe 0000:bf:00.0: [drm] device wedged, needs recovery

[] ------------[ cut here ]------------

[] DEBUG_LOCKS_WARN_ON(lock->magic != lock)

[] WARNING: CPU: 48 PID: 312 at kernel/locking/mutex.c:564 __mutex_lock+0x8a1/0xe60

...

[] RIP: 0010:__mutex_lock+0x8a1/0xe60

[] mutex_lock_nested+0x1b/0x30

[] xe_guc_submit_wedge+0x80/0x2b0 [xe]