target/arm: Use tcg_gen_qemu_{ld, st}_i128 in gen_sve_{ld, st}r

target/arm: Use tcg_gen_qemu_{ld, st}_i128 in gen_sve_{ld, st}r

Round len_align to 16 instead of 8, handling an odd 8-byte as part
of the tail.  Use MO_ATOM_NONE to indicate that all of these memory
ops have only byte atomicity.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230530191438.411344-8-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>