net: phy: meson-gxl: improve link-up behavior

Sometimes the link comes up but no data flows. This patch fixes
this behavior. It's not clear what's the root cause of the issue.

According to the tests one other link-up issue remains.
In very rare cases the link isn't even reported as up.

Fixes: 84c8f773 ("net: phy: meson-gxl: remove the use of .ack_callback()")
Tested-by: Erico Nunes <nunes.erico@gmail.com>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/e3473452-a1f9-efcf-5fdd-02b6f44c3fcd@gmail.com


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