Merge branch 'stmmac-mdio-compat'

Merge branch 'stmmac-mdio-compat'

Phil Reid says:

====================
stmmac: create of compatible mdio bus for stmacc driver

Provide ability to specify a fixed phy in the device tree and
retain the mdio bus if no phy is found. This is needed where
a dsa is connected via a fixed phy and uses the mdio bus for config.
Fixed ptp ref clock calculatins for the stmmac when ptp ref clock
is running at <= 50Mhz. Also add device tree setting to config
ptp clk source on socfpga platforms.

Changes from V5:
- Restore behaviour of unregister mdio bus when no phys found
  if there is no device tree node create the bus.
- Modify condition to allocate mdio_base_data conditional
  on fixed phy presece as well. Maintains existing behaviour
  in conditions where a fixed phy is not present.

Changes from V4:
- Restore #ifdef CONFIG_OF around setting of reset_gpio.
  Member doesn't exist when this isn't defined.

Changes from V3:
- Use if (IS_ENABLED(CONFIG_OF)) instead of #if.
  Reorder some code to reduce if statements.
- of_mdiobus_register already falls back to mdiobus_register
- Tested on system with CONFIG_OF

Changes from V2:
- Formatting, spaces & lines > 80 chars. Using checkpatch
- Drop PTP register debugfs patch.

Changes from V1:
- Fixed mismatch doc / code for ptp_ref_clk dt node.
- Remove unit address from doc example.
====================

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