ARM: dts: imx6dl-colibri: Fix I2C pinmuxing

Fix names of extra pingroup node and property for gpio bus recovery.
Without the change i2c2 is not functional.

Fixes: 56f0df6b ("ARM: dts: imx*(colibri|apalis): add missing recovery modes to i2c")
Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>