net: sfp: add support for a couple of copper multi-rate modules

Add support for the Fiberstore SFP-10G-T and Walsun HXSX-ATRC-1
modules. Internally, the PCB silkscreen has what seems to be a part
number of WT_502. Fiberstore use v2.2 whereas Walsun use v2.6.

These modules contain a Marvell AQrate AQR113C PHY, accessible through
I2C 0x51 using the "rollball" protocol. In both cases, the PHY is
programmed to use 10GBASE-R with pause-mode rate adaption.

Unlike the other rollball modules, these only need a four second delay
before we can talk to the PHY.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/E1q0JfS-006Dqc-8t@rmk-PC.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>