net: phy: mdio-bcm-unimac: Remove asp-v2.0

Remove asp-v2.0 which will no longer be supported.

Signed-off-by: Justin Chen <justin.chen@broadcom.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://patch.msgid.link/20250422233645.1931036-5-justin.chen@broadcom.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>