dt-bindings: arm: ux500: Document samsung,golden compatible

The Samsung Galaxy S III mini ("samsung-golden") can now boot
mainline Linux; document the samsung,golden compatible that is
used in its device tree.

Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Link: https://lore.kernel.org/r/20191219202052.19039-4-stephan@gerhold.net


Signed-off-by: Linus Walleij <linus.walleij@linaro.org>