dt-bindings: arm: amazon: add Amazon Annapurna Labs Alpine V3

This patch adds DT bindings info for Amazon Annapurna Labs Alpine V3.

Link: https://lore.kernel.org/r/20200724132654.16549-6-hhhawa@amazon.com


Signed-off-by: Hanna Hawa <hhhawa@amazon.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Antoine Tenart <antoine.tenart@bootlin.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>