ARM: dts: imx: Add TDA19971 HDMI Receiver to GW551x

The GW551x has a front-panel microHDMI connector routed to a TDA19971
which is connected the the IPU CSI.

Signed-off-by: Tim Harvey <tharvey@gateworks.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>