dt-bindings: memory: Add Baikal-T1 L2-cache Control Block binding

dt-bindings: memory: Add Baikal-T1 L2-cache Control Block binding

There is a single register provided by the SoC system controller,
which can be used to tune the L2-cache RAM up. It only provides a way
to change the L2-RAM access latencies. So aside from "be,bt1-l2-ctl"
compatible string the device node can be optionally equipped with the
properties of Tag/Data/WS latencies.

Link: https://lore.kernel.org/r/20200526125928.17096-4-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Olof Johansson <olof@lixom.net>
Cc: linux-mips@vger.kernel.org
Cc: soc@kernel.org
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>