Fix comment typos in permutation spelling

Fix comment typos in permutation spelling

Noticed two weird ways to spell permutation in some comments.

2026-02-07  Jakub Jelinek  <jakub@redhat.com>

	* optabs.cc (expand_vec_perm_const): Comment spelling fix,
	permuation -> permutation.
	* config/arm/arm.cc (arm_evpc_neon_vtbl): Likewise.
	* config/loongarch/loongarch.cc (loongarch_try_expand_lsx_vshuf_const):
	Comment spelling fix, permuatation -> permutation.
	(loongarch_is_elem_duplicate): Likewise.  Comment spelling fix,
	permuation -> permutation.