Soft-float cleanup

- UseSoftFloat target option is removed from upstream.  Remove its use
  and update the comment on how to skip FPU and use software
  floating-point.
- Cleanup comment and remove a stale TODO about auto-detecting the
  presence of hardware FPU.  It is unlikely that any processor doesn't
  have an FPU these days.

Change-Id: Ib0c0efc7e9dbd3a525aa714c8771247e2d96f9f2
1 file changed