fpu: Build only once

fpu: Build only once

Now we have removed all the target-specifics from the softfloat code,
we can switch to building it once for the whole system rather than
once per target.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Tested-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20250224111524.1101196-13-peter.maydell@linaro.org
Message-id: 20250217125055.160887-11-peter.maydell@linaro.org