DEVELOPERS: add Romain Naour for toolchain topic

DEVELOPERS: add Romain Naour for toolchain topic

The first time I worked on the Buildroot's toolchain infra
was to add support for the Sourcery Codebench Standard
(licenced) edition toolchain (from Mentor Graphics) for
x86 target [1]. The series was rejected though.

But the knowledge gained from this work served to refactor
the toolchain-external infra in Buildroot [2].

Nowadays, I'm using toolchains-builder project to do
some toolchain build testing to keep GNU tools up to date
in Buildroot.

[1] http://lists.busybox.net/pipermail/buildroot/2014-November/112036.html
[2] http://lists.busybox.net/pipermail/buildroot/2016-October/175433.html
[3] https://gitlab.com/kubu93/toolchains-builder/

Signed-off-by: Romain Naour <romain.naour@smile.fr>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>