net: ethernet: stmmac: reset force speed bit for ipq806x

net: ethernet: stmmac: reset force speed bit for ipq806x

Some bootloader may set the force speed regs even if the actual
interface should use autonegotiation between PCS and PHY.
This cause the complete malfuction of the interface.

To fix this correctly reset the force speed regs if a fixed-link is not
defined in the DTS. With a fixed-link node correctly configure the
forced speed regs to handle any misconfiguration by the bootloader.

Reported-by: Mark Mentovai <mark@moxienet.com>
Co-developed-by: Mark Mentovai <mark@moxienet.com>
Signed-off-by: Mark Mentovai <mark@moxienet.com>
Signed-off-by: Christian 'Ansuel' Marangi <ansuelsmth@gmail.com>
Link: https://lore.kernel.org/r/20220614112228.1998-2-ansuelsmth@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>