Merge branch 'Ingenic-SOC-mac-support'

Zhou Yanjie says:

====================
Add Ingenic SoCs MAC support.

v2->v3:
1.Add "ingenic,mac.yaml" for Ingenic SoCs.
2.Change tx clk delay and rx clk delay from hardware value to ps.
3.return -EINVAL when a unsupported value is encountered when
  parsing the binding.
4.Simplify the code of the RGMII part of X2000 SoC according to
  Andrew Lunn’s suggestion.
5.Follow the example of "dwmac-mediatek.c" to improve the code
  that handles delays according to Andrew Lunn’s suggestion.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>