ARM: mx5/mx51_babbage: Move GPIO initialization for USB PHY Reset line to common place

The USB PHY Reset GPIO can be configured in the same place as the other GPIOs.

While at it rename the pin as BABBAGE_USB_PHY_RESET to make clearer its purpose.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>