Convert drivers to use the new of_graph_get_remote_node() helper
instead of parsing the endpoint node and then getting the remote device
node. Now drivers can just specify the device node and which
port/endpoint and get back the connected remote device node. The details
of the graph binding are nicely abstracted into the core OF graph code.

This changes some error messages to debug messages (in the graph core).
Graph connections are often "no connects" depending on the particular
board, so we want to avoid spurious messages. Plus the kernel is not a
DT validator.
Signed-off-by: NRob Herring <robh@kernel.org>
Acked-by: NNeil Armstrong <narmstrong@baylibre.com>
Tested-by: NLiviu Dudau <liviu.dudau@arm.com>
Tested-by: NEric Anholt <eric@anholt.net>
Tested-by: NJyri Sarha <jsarha@ti.com>
Tested by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: NSean Paul <seanpaul@chromium.org>