There are two chip pins named TXDLY and RXDLY which actually adds the 2ns
delays to TXC and RXC for TXD/RXD latching. These two pins can config via
4.7k-ohm resistor to 3.3V hw setting, but also config via software setting
(extension page 0xa4 register 0x1c bit13 12 and 11).

The configuration register definitions from table 13 official PHY datasheet:
PHYAD[2:0] = PHY Address
AN[1:0] = Auto-Negotiation
Mode = Interface Mode Select
RX Delay = RX Delay
TX Delay = TX Delay
SELRGV = RGMII/GMII Selection

This table describes how to config these hw pins via external pull-high or pull-
low resistor.

It is a misunderstanding that mapping it as register bits below:
8:6 = PHY Address
5:4 = Auto-Negotiation
3 = Interface Mode Select
2 = RX Delay
1 = TX Delay
0 = SELRGV
So I removed these descriptions above and add related settings as below:
14 = reserved
13 = force Tx RX Delay controlled by bit12 bit11
12 = Tx Delay
11 = Rx Delay
10:0 = Test && debug settings reserved by realtek

Test && debug settings are not recommend to modify by default.

Fixes: f81dadbc ("net: phy: realtek: Add rtl8211e rx/tx delays config")
Signed-off-by: Willy Liu <willy.liu@realtek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>