USB: ehci-omap: Tweak PHY initialization sequence

For PHY mode, the PHYs must be brought out of reset
before the EHCI controller is started.

This patch fixes the issue where USB devices are not found
on Beagleboard/Beagle-xm if USB has been started previously
by the bootloader. (e.g. by "usb start" command in u-boot)

Tested on Beagleboard, Beagleboard-xm and Pandaboard.

Issue present on 3.10 onwards.

Reported-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Tested-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Roger Quadros <rogerq@ti.com>
Cc: stable <stable@vger.kernel.org> # 3.10
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>