usb: chipidea: ci13xxx_imx: remove 'phy_np'

There is no need to keep a local 'phy_np' as we can directly use the private
structure in data->phy_np.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>