ARM: dts: i.MX6: sync imx6q and imx6dl pinmux entries

The i.MX6Q and i.MX6DL are pin compatible, so the pinmux entries
should be in sync. This patch systematically adds the pinmux entries
missing from the imx6q to the imx6dl file.
Some name inconsistencies and whitespace damage is fixed along the
way.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>