rockchip: board: popmetal: de-assert the host rst pin in board init

The PopMetal board have a on board FE1.1 usb 2.0 hub which connect to
the usb host port, we need to de-assert its reset pin to enable it.

Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Acked-by: Simon Glass <sjg@chromium.org>
Added rockchip: tag:
Signed-off-by: Simon Glass <sjg@chromium.org>