arch: re-order the entries in the float choice

Re-order the three entries in the float choice, in a more sensible
order, ie:
- all hard-float options come first, then soft-float
- options that use the FPU are marked so: hard and softfp
- options that do not use the FPU are marked so: software

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>

 #!/bin/sh

 set -e

 printf "Running autoconf...\n"

 autoconf -Wall --force

 printf "Done. You may now run:\n    ./configure\n"