pinctrl: renesas: rzt2h: Fix device node leak in rzt2h_gpio_register()

pinctrl: renesas: rzt2h: Fix device node leak in rzt2h_gpio_register()

When calling of_parse_phandle_with_fixed_args(), the caller is
responsible for calling of_node_put() to release the device node
reference.

In rzt2h_gpio_register(), the driver fails to call of_node_put() to
release the reference in of_args.np, which causes a memory leak.

Add the missing of_node_put() call to fix the leak.

Fixes: 34d4d093077a ("pinctrl: renesas: Add support for RZ/T2H")
Signed-off-by: Felix Gu <ustc.gu@gmail.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/20260127-rzt2h-v1-1-86472e7421b8@gmail.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>