uboot-imx

board: sama5d2_xplained: clean up macb init code

Because the MACB driver supports the driver model and device tree,
the pins configuration and clock enabling are handled by the
pinctrl driver and clock driver, remove this hardcoded init code.

The USB Ether init code is removed as well.

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>