usb: dwc3: imx8mp: fix memory leak on probe failure path

usb: dwc3: imx8mp: fix memory leak on probe failure path

When platform_get_drvdata() returns NULL and probe defers, the error
path jumps to the 'depopulate' label, skipping put_device() for the
reference acquired by of_find_device_by_node(). This extra reference
prevents the child platform device from being freed when
of_platform_depopulate() is called, resulting in memory leaks reported
by kmemleak:

  unreferenced object 0xffff0000c92c1480 (size 64):
    comm "kworker/u16:2", pid 50, jiffies 4294895789
    backtrace (crc 49d507d0):
      kmemleak_alloc+0x34/0x40
      __kmalloc_noprof+0x430/0x670
      of_device_alloc+0xec/0x26c
      of_platform_device_create_pdata+0x60/0x1f0
      of_platform_bus_create+0x290/0x610
      of_platform_populate+0x74/0x118
      dwc3_imx8mp_probe+0x228/0x734

Fixes: 86767625f525 ("usb: dwc3: imx8mp: disable auto suspend for host role")
Signed-off-by: Xiaolei Wang <xiaolei.wang@windriver.com>
Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://patch.msgid.link/20260401134938.686748-1-xiaolei.wang@windriver.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>