usb: chipidea: remove the unnecessary delay after clear portsc.phcd

The individual PHY driver should take this responsibility if it
needs to delay between clear portsc.phcd and let the phy leave
low power mode.

Signed-off-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>