arch: allow adding a suffix to the arch-part of a tuple

For some architectures, it is legit to have an alternate value in the
'architecture' part of the tuple. For example:
armv5te-*
armv7a8-*

Besides, some packages expect the tuple to reflect the arch variant
(eg. openMPI) to detect the variant's capabilities (eg. atomic
primitives).

This patch adds an option for the user to specify a suffix to be added
to the arch-part of the tuple.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Message-ID: <20130120225822.GS6838@1wt.eu>
Patch-Id: 213994
[yann.morin.1998@free.fr: make it a suffix, not an override]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>

 # This file declares functions to install the kernel headers for mingw64

 # Copyright 2012 Yann Diorcet

 # Licensed under the GPL v2. See COPYING in the root of this package

 CT_DoKernelTupleValues() {

     # Even we compile for x86_64 target architecture, the target OS have to

     # bet mingw32 (require by gcc and mingw-w64)

     CT_TARGET_KERNEL="mingw32"

     CT_TARGET_SYS=

 }

 do_kernel_get() {

     :

 }

 do_kernel_extract() {

     :

 }

 do_kernel_headers() {

    :

 }