[AArch64] Remove aarch64_simd_attr_length_move

[AArch64] Remove aarch64_simd_attr_length_move

	* config/aarch64/aarch64.c (aarch64_simd_attr_length_move): Delete.
	* config/aarch64/aarch64-protos.h (aarch64_simd_attr_length_move):
	Delete prototype.
	* config/aarch64/iterators.md (insn_count): Add descriptive comment.
	* config/aarch64/aarch64-simd.md (*aarch64_mov<mode>, VSTRUCT modes):
	Remove use of aarch64_simd_attr_length_move, set length attribute
	directly.
	(*aarch64_be_movoi): Likewise.
	(*aarch64_be_movci): Likewise.
	(*aarch64_be_movxi): Likewise.

From-SVN: r236916