uboot-imx

board: sama5d2_xplained: Clean up code

Since the introduction of pinctrl and clk driver, and the dts file,
remove unneeded the pin configurations and the clock enabling code.

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Andreas Bießmann <andreas.devel@googlemail.com>