clk: imx: imx6q: Fix device node reference leak in of_assigned_ldb_sels()

clk: imx: imx6q: Fix device node reference leak in of_assigned_ldb_sels()

The function of_assigned_ldb_sels() calls of_parse_phandle_with_args()
but never calls of_node_put() to release the reference, causing a memory
leak.

Fix this by adding proper cleanup calls on all exit paths.

Fixes: 5d283b083800 ("clk: imx6: Fix procedure to switch the parent of LDB_DI_CLK")
Signed-off-by: Felix Gu <ustc.gu@gmail.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Link: https://patch.msgid.link/20260203-clk-imx6q-v3-2-6cd2696bb371@gmail.com
Signed-off-by: Abel Vesa <abel.vesa@oss.qualcomm.com>