Merge branch 'ethtool-master-slave'

Oleksij Rempel says:

====================
provide support for PHY master/slave configuration

changes v6:
- use NL_SET_ERR_MSG_ATTR in ethnl_update_linkmodes
- add sanity checks in the ioctl interface
- use bool for ethnl_validate_master_slave_cfg()

changes v5:
- set MASTER_SLAVE_CFG_UNSUPPORTED as default value
- send a netlink error message on validation error
- more code fixes

changes v4:
- rename port_mode to master_slave
- move validation code to net/ethtool/linkmodes.c
- add UNSUPPORTED state and avoid sending unsupported fields
- more formatting and naming fixes
- tja11xx: support only force mode
- tja11xx: mark state as unsupported

changes v3:
- provide separate field for config and state.
- make state rejected on set
- add validation

changes v2:
- change names. Use MASTER_PREFERRED instead of MULTIPORT
- configure master/slave only on request. Default configuration can be
  provided by PHY or eeprom
- status and configuration to the user space.
====================

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