target/s390x: Use a single return for helper_divs32/u32

target/s390x: Use a single return for helper_divs32/u32

Pack the quotient and remainder into a single uint64_t.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
v2: Fix operand ordering; use tcg_extr32_i64.