arm64: defconfig: Enable CONFIG_DRM_IMX_LCDIF

Enable CONFIG_DRM_IMX_LCDIF so that display output can be functional
by default on the imx8mp-evk board.

Signed-off-by: Fabio Estevam <festevam@denx.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>