usb: dwc3: meson-g12a: do post init to fix broken usb after resumption

commit 1fa206bb upstream.

Device connected to usb otg port of GXL-based boards can not be
recognised after resumption, doesn't recover even if disconnect and
reconnect the device. dmesg shows it disconnects during resumption.

[   41.492911] usb 1-2: USB disconnect, device number 3
[   41.499346] usb 1-2: unregistering device
[   41.511939] usb 1-2: unregistering interface 1-2:1.0

Calling usb_post_init() will fix this issue, and it's tested and
verified on libretech's aml-s905x-cc board.

Cc: stable@vger.kernel.org # v5.8+
Fixes: c9999337

 ("usb: dwc3: Add Amlogic G12A DWC3 glue")
Signed-off-by: Luke Lu <luke.lu@libre.computer>
Acked-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20230809212911.18903-1-luke.lu@libre.computer
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>