uboot-imx

x86: link: Add pin configuration to the device tree

At present pin configuration on link does not use the standard mechanism,
but some rather ugly custom code. As a first step to resolving this, add the
pin configuration to the device tree.

Four of the GPIOs must be available before relocation (for SDRAM pin
strapping).

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>