UPLI PHY connected to USBH1 on Babbage board seem to need a special
reset sequence in which STP signal gets asserted for a short period of
time. Without this sequnce running "usb" results in timeout and no USB
devices found.

Similar reset sequences can be found in Babbage board code in U-Boot
as well as efikamx_usb_init() in Barebox.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>