phy: ti: j721e-wiz: Fix device node reference leak in wiz_get_lane_phy_types()

The serdes device_node is obtained using of_get_child_by_name(),
which increments the reference count. However, it is never put,
leading to a reference leak.

Add the missing of_node_put() calls to ensure the reference count is
properly balanced.

Fixes: 7ae14cf581f2 ("phy: ti: j721e-wiz: Implement DisplayPort mode to the wiz driver")
Suggested-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Felix Gu <ustc.gu@gmail.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Link: https://patch.msgid.link/20260212-wiz-v2-1-6e8bd4cc7a4a@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>