Add the binding document for the external memory controller (EMC) which
communicates with external LPDDR4 devices. It includes the bindings of
the EMC node and a sub-node of EMC table which under the reserved memory
node. The EMC table contains the data of the rates that EMC supported.
Signed-off-by: Joseph Lo <josephl@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Rob Herring <robh@kernel.org>