phy: lynx-28g: avoid returning NULL in of_xlate() function

phy: lynx-28g: avoid returning NULL in of_xlate() function

Sashiko points out that _of_phy_get() does not support a NULL returned
output from phy_provider->of_xlate(), just a valid pointer or a
pointer-encoded error.

When lynx_28g_probe() -> for_each_available_child_of_node() skips
over lanes which have OF nodes with status = "disabled", the
priv->lane[idx].phy pointer will remain NULL.

This NULL pointer may be propagated to lynx_28g_xlate() if the device
tree contains a phandle to the disabled lane AND fw_devlink did not
block probing for the consumer. In that case, the PHY core will crash
when trying to dereference the NULL phy pointer.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://patch.msgid.link/20260610151952.2141019-2-vladimir.oltean@nxp.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>