ARM: dts: imx6qdl-wandboard: add scl/sda gpios definitions for i2c bus recovery

The i2c bus on imx6qdl-wandboard has intermittent issues where SDA can freeze
on low level at the end of transaction so the bus can no longer work. This
impacts reading of EDID data leading to incorrect TV resolution and no audio.

This scenario is improved by adding scl/sda gpios definitions to implement the
i2c bus recovery mechanism.

Signed-off-by: Dima Azarkin <azdmg@outlook.com>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>