net: stmmac: dwmac-intel: remove checking for fixed link

With the new default_an_inband functionality in phylink, there is no
need to check for a fixed link when this flag is set, since a fixed
link will now override default_an_inband.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Halaney <ahalaney@redhat.com>
Link: https://lore.kernel.org/r/E1sCJNB-00EcrJ-7L@rmk-PC.armlinux.org.uk


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