net: phy: marvell: implement cable-test for 88E308X/88E609X family

net: phy: marvell: implement cable-test for 88E308X/88E609X family

This commit implements VCT in 88E308X/88E609X Family.

It require two workarounds with some magic configuration.
Regular use require only one register configuration. But Open Circuit
require second workaround.
It cause implementation two phases for fault length measuring.

Fast Ethernet PHY have implemented very simple version of VCT. It's
complitley different than vct5 or vct7.

Signed-off-by: Pawel Dembicki <paweldembicki@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20240402201123.2961909-3-paweldembicki@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>