ARM: dts: imx: Avoid colliding 'display' node and property names

ARM: dts: imx: Avoid colliding 'display' node and property names

While properties and child nodes with the same name are valid DT, the
practice is not encouraged. Furthermore, the collision is problematic for
YAML encoded DT. Let's just avoid the issue and rename the nodes.

Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: NXP Linux Team <linux-imx@nxp.com>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>