drm/xe: Fix BUG_ON during bind with prefetch

drm/xe: Fix BUG_ON during bind with prefetch

It was missed that print_op needs to include DRM_GPUVA_OP_PREFETCH.

Else we hit the impossible BUG_ON:
[  886.371040] ------------[ cut here ]------------
[  886.371047] kernel BUG at drivers/gpu/drm/xe/xe_vm.c:2234!
[  886.371216] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
[  886.371229] CPU: 1 PID: 3132 Comm: xe_exec_fault_m
[  886.371257] RIP: 0010:vm_bind_ioctl_ops_create+0x45f/0x470 [xe]
...
[  886.371517] Call Trace:
[  886.371525]  <TASK>
[  886.371531]  ? __die_body+0x1a/0x60
[  886.371546]  ? die+0x38/0x60
[  886.371557]  ? do_trap+0x10a/0x120
[  886.371568]  ? vm_bind_ioctl_ops_create+0x45f/0x470 [xe]

v2: add debug print for PREFETCH in print_op

Fixes: b06d47be7c83 ("drm/xe: Port Xe to GPUVA")
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Brian Welty <brian.welty@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>