net: usb: asix_devices: add phy_mask for ax88772 mdio bus

Without setting phy_mask for ax88772 mdio bus, current driver may create
at most 32 mdio phy devices with phy address range from 0x00 ~ 0x1f.
DLink DUB-E100 H/W Ver B1 is such a device. However, only one main phy
device will bind to net phy driver. This is creating issue during system
suspend/resume since phy_polling_mode() in phy_state_machine() will
directly deference member of phydev->drv for non-main phy devices. Then
NULL pointer dereference issue will occur. Due to only external phy or
internal phy is necessary, add phy_mask for ax88772 mdio bus to workarnoud
the issue.

Closes: https://lore.kernel.org/netdev/20250806082931.3289134-1-xu.yang_2@nxp.com


Fixes: e532a096 ("net: usb: asix: ax88772: add phylib support")
Cc: stable@vger.kernel.org
Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
Tested-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://patch.msgid.link/20250811092931.860333-1-xu.yang_2@nxp.com


Signed-off-by: Paolo Abeni <pabeni@redhat.com>