The imx6q and imx6dl are two pin-to-pin compatible SoCs.  The same board
design can work with either chip plugged into the socket, e.g. sabresd
and sabreauto boards.

We currently define pin groups in imx6q.dtsi and imx6dl.dtsi
respectively because the pad macro names are different between two
chips.  This brings a maintenance burden on having the same label point
to the same pin group defined in two places.

The patch replaces prefix MX6Q_ and MX6DL_ with MX6QDL_ for both SoCs
pad macro names.  Then the pin groups becomes completely common between
imx6q and imx6dl and can just be moved into imx6qdl.dtsi, so that the
long term maintenance of imx6q/dt pin settings becomes easier.

Unfortunately, the change brings some dramatic diff stat, but it's all
about DTS file, and the ultimate net diff stat is good.
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>

The uart2 in the imx6q-arm2 board is used as a DTE uart,
this patch adds the necessary DTE pads for uart2.
Signed-off-by: NHuang Shijie <b32955@freescale.com>
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>

The imx6dl is a derivative of imx6q with very limited difference.  These
two SoCs are so compatible that they can be handled as one platform in
software.  That said, we will not have target SOC_IMX6DL but just
reusing SOC_IMX6Q.   That's why the pinctrl-imx6dl driver is added here
with symbol PINCTRL_IMX6Q controlling the build of it.
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>