UPSTREAM: net: phy: dp83867: Add lane swapping support in the DP83867 TI's PHY driver

UPSTREAM: net: phy: dp83867: Add lane swapping support in the DP83867 TI's PHY driver

This patch adds support for enabling or disabling the lane swapping (called
"port mirroring" in PHY's CFG4 register) feature of the DP83867 TI's PHY
device.

One use case is when bootstrap configuration enables this feature (because
of e.g. LED_0 wrong wiring) so then one needs to disable it in software
(at u-boot/Linux).

Signed-off-by: Lukasz Majewski <lukma@denx.de>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit fc6d39c39581f3c12c95f166ce95ef8beb2047e8)
Change-Id: Iea19a3e02a5072e5b3ab2b4ee33befd5805100e2
Signed-off-by: Jacob Chen <jacob2.chen@rock-chips.com>