interconnect: Add imx core driver

This adds support for i.MX SoC family to interconnect framework.

Platform drivers can describe the interconnect graph and several
adjustment knobs where icc node bandwidth is converted to a
DEV_PM_QOS_MIN_FREQUENCY request.

The interconnect provider is probed through the main NOC device and
other adjustable nodes on the same graph are found from a
fsl,scalable-nodes phandle array property.

Signed-off-by: Alexandre Bailon <abailon@baylibre.com>
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Tested-by: Martin Kepplinger <martin.kepplinger@puri.sm>
Link: https://lore.kernel.org/r/35920e673df6c04cbbb7d877a7d4ba25fd91a784.1586174566.git.leonard.crestez@nxp.com


Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>