net: add driver for Synopsys Ethernet QoS device

net: add driver for Synopsys Ethernet QoS device

This driver supports the Synopsys Designware Ethernet QoS (Quality of
Service) a/k/a eqos IP block, which is a different design than the HW
supported by the existing designware.c driver. The IP supports many
options for bus type, clocking/reset structure, and feature list. This
driver currently supports the specific configuration used in NVIDIA's
Tegra186 chip, but should be extensible to other combinations quite
easily, as explained in the source.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Simon Glass <sjg@chromium.org> # V1
Acked-by: Joe Hershberger <joe.hershberger@ni.com>