drm/xe: Rename exec_queue_kill_compute to xe_vm_remove_compute_exec_queue

Much better name and aligns with xe_vm_add_compute_exec_queue. As part
of the rename, move the implementation from xe_exec_queue.c to xe_vm.c.

Suggested-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>