net: usb: asix: do not force pause frames support

We should respect link partner capabilities and not force flow control
support on every link. Even more, in current state the MAC driver do not
advertises pause support so we should not keep flow control enabled at
all.

Fixes: e532a096

 ("net: usb: asix: ax88772: add phylib support")
Reported-by: Anton Lundin <glance@acc.umu.se>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Tested-by: Anton Lundin <glance@acc.umu.se>
Link: https://lore.kernel.org/r/20220624075139.3139300-2-o.rempel@pengutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>