omap3_beagle: Don't use ulpi_reset

Fixes this error message when USB is started.
"ULPI: ulpi_reset: failed writing reset bit"

It is pointless to manually reset the ULPI as the USB Host
Reset and PHY RESET line should take care of that.

Reported-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Signed-off-by: Roger Quadros <rogerq@ti.com>