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>

 CT_EXPERIMENTAL=y

 CT_LOCAL_TARBALLS_DIR="${HOME}/src"

 CT_SAVE_TARBALLS=y

 CT_CONFIG_SHELL_SH=y

 CT_LOG_EXTRA=y

 CT_ARCH_avr32=y

 CT_BINUTILS_V_2_18a=y

 CT_CC_V_4_2_2=y

 CT_LIBC_NEWLIB_V_1_17_0=y