usb: omap: ulpi: fix ulpi transceiver access

usb: omap: ulpi: fix ulpi transceiver access

This patch fix the omap access to the transceiver
configuration registers using the ulpi bus. As reported by
the documentation the bit31 is used only to check if the
transaction is done or still running and the reading and
writing operation have different offset and have different
values. What we need to do at the end of a transaction is
leave the bus in done state. Anyway an error using the ulpi
omap register is not recoverable so any error give out the
usage of this interface.

Tested on a custom OMAP5430 board with a TUSB1210 ULPI PHY
on USBB1.

Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
Acked-by: Igor Grinberg <grinberg@compulab.co.il>
Tested-by: Lubomir Popov <lpopov@mm-sol.com>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Marek Vasut <marex@denx.de>
Cc: Tom Rini <trini@ti.com>