This patch configures the I2C bus timing registers according
to information passed via DT. Currently, 100kHz and 400kHz
modes are supported.

The TIMING2 register value is wrong in the documentation for
i.MX28! This was found and fixed by:
  Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: NMarek Vasut <marex@denx.de>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

Signed-off-by: NShawn Guo <shawn.guo@linaro.org>

Signed-off-by: NShawn Guo <shawn.guo@linaro.org>

Signed-off-by: NShawn Guo <shawn.guo@linaro.org>

It adds gpio support for device tree boot.
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>

Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Huang Shijie <b32955@freescale.com>
Signed-off-by: NDong Aisheng <dong.aisheng@linaro.org>
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>
Acked-by: NMarek Vasut <marex@denx.de>
Acked-by: NVinod Koul <vinod.koul@intel.com>

This patch includes basic dt support which can boot via nfs rootfs.
Signed-off-by: NDong Aisheng <dong.aisheng@linaro.org>
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>
Acked-by: NMarek Vasut <marex@denx.de>