arch/avr32: Fix download of header files

This patch fixes the download of the avr32 headers in crosstool-ng by
fetching them directly from Atmel's web site instead of the now-broken URL
given by the original author of the avr32-header-fetching modification,
who fetched them from a copy on his own, now-defunct server.

It also adds the necessary logic to extract from a zip file, as that is
how the headers are packaged.

To configure it for avr32 after launching ct-ng menuconfig in an empty
directory:

Paths and misc options ->
Shell to use as CONFIG_SHELL = sh
Target options ->
Target Architecture = avr32
Toolchain options ->
Tuple's alias = avr32
Binary utilities ->
binutils version = 2.18a
C compiler
gcc version = 4.2.2
C-library
newlib version = 1.17.0
Enable IOs on long long = yes
Enable IOs on floats and doubles = yes
Disable the syscalls supplied with newlib = yes

CONFIG_SHELL is necessary to get round the "fragment: command not
found" bug when binutils-2.18 is configured using bash.

Prepared against crosstool-ng mercurial trunk on 31 March 2012.

Signed-off-by: Martin Guy <martinwguy@gmail.com>
[yann.morin.1998@free.fr: update bundles sample accordingly]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Message-Id: <CAL4-wQrg_NQ7jm-NCADqeyQr9twyhtx42OUGNThP6gWeqZc=kw@mail.gmail.com>
Patchwork-Id: 232612

 This is the README for crosstool-NG

 Crosstool-NG follows the autoconf dance. So, to get you

 kick-started, just run:

     ./configure --help

 If you are using a development snapshot, you'll have to

 create the configure script, first. Just run:

     ./bootstrap

 You will find the documentation in the directory 'docs'.

 Here is a quick overview of what you'll find there:

   0 - Table of content

   1 - Introduction

   2 - Installing crosstool-NG

   3 - Configuring a toolchain

   4 - Building the toolchain

   5 - Using the toolchain

   6 - Toolchain types

   7 - Contributing

   8 - Internals

   A - Credits

   B - Known issues

   C - Misc. tutorials

 You can also point your browser at:

   http://crosstool-ng.org/

 Aloha!