binutils/binutils: 2.23.2 is a 2_23_or_later (ie. has gold)

Thus spake Niels:
This commit adds support for binutils 2.23.2

http://crosstool-ng.org/hg/crosstool-ng/rev/bc4b36e3df0c

However, in 'config/binutils/binutils.in <http://binutils.in>' the
Kconfig option to select this version of binutils does not automatically
select the symbol 'BINUTILS_2_23_or_later'. This makes gold unavailable
for the latest version of binutils. I'm not sure whether this is on
purpose or not, my impression is that you forgot to add the line "select
BINUTILS_2_23_or_later".

The problem still persists in the latest version in the repository
(032ebcc89c96).

Reported-by: Niels Penneman <niels@penneman.org>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>

 # Options specific to crosstool-NG acting as a backend

 config IS_A_BACKEND

     string

     option env="CT_IS_A_BACKEND"

 config BACKEND

     bool

     default y if IS_A_BACKEND = "y" || IS_A_BACKEND = "Y"

 config BACKEND_ARCH

     string

     option env="CT_BACKEND_ARCH"

 config BACKEND_KERNEL

     string

     option env="CT_BACKEND_KERNEL"

 config BACKEND_LIBC

     string

     option env="CT_BACKEND_LIBC"