config: reorder the architectures sub-menu

Re-organise the sub-menu so that:
- the archs list comes first,
- followed by archs generic options
- followed by archs specific options

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

 reporter_name="Yann E. MORIN"

 reporter_url="http://ymorin.is-a-geek.org/projects/crosstool"

 reporter_comment="Experimental toolchain for ARM cortex-m3 in Thumb-only, noMMU, and newlib."