ENGR00258491-2 msl-mx6: usb: put PHY to be out of low power explicitly

ENGR00258491-2 msl-mx6: usb: put PHY to be out of low power explicitly

We have wrong understanding that reset controller will put PHY
to be out of low power automatically, but in fact, it is not.
So, we should put PHY to be out of low power explicitly if the
portsc.phcd = 1 before we need to access controller's register.
Some register writing will hang system (eg,PERIODICLISTBASE),
some reading will not get the correct value (eg, otgsc).

Signed-off-by: Peter Chen <peter.chen@freescale.com>