qemu/atomic: Finish renaming atomic128-cas.h headers

qemu/atomic: Finish renaming atomic128-cas.h headers

The aarch64 header was not renamed with the others, meaning it
was skipped in favor of the generic version.

Cc: qemu-stable@nongnu.org
Fixes: 15606965400b ("qemu/atomic: Rename atomic128-cas.h headers using .h.inc suffix")
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20250815122653.701782-2-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>