targets (various): use softfloat-helpers.h where we can

targets (various): use softfloat-helpers.h where we can

Generally the cpu and non-FP helper files just want to manipulate the
softfloat flags. For this they can just use the -helpers.h include
which brings in a minimal number of inline helpers.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>