usb: dwc3-am62: Fix an OF node leak in phy_syscon_pll_refclk()

phy_syscon_pll_refclk() leaks an OF node obtained by
of_parse_phandle_with_fixed_args(), thus add an of_node_put() call.

Cc: stable <stable@kernel.org>
Fixes: e8784c0a ("drivers: usb: dwc3: Add AM62 USB wrapper driver")
Signed-off-by: Joe Hattori <joe@pf.is.s.u-tokyo.ac.jp>
Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/20250109001638.70033-1-joe@pf.is.s.u-tokyo.ac.jp


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>