ARM: dts: imx6qdl: phytec: Add support for optional PEB-AV-02 LCD adapter

The PEB-AV-02 expansion adapter extends the phyBOARD-Mira boards to
connect parallel LCD displays, either with capacitive or resistive
touch.

Signed-off-by: Yunus Bas <y.bas@phytec.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>