Socionext SynQuacer(SC2A11) was already supported and
Developerbox(Linaro's 96Boards EE compliant board) is
publicly available.
Let's add in Supported Platforms.

Signed-off-by: Masahisa Kojima <masahisa.kojima@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>