ARM: dts: renesas: armadillo800eva: Add LCD panel

Describe the 5" WVGA TFT LCD panel on the Armadillo-800-EVA development
board, and enable the LCD controller that drives it.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Link: https://lore.kernel.org/r/278339322dcaaedc0d68fc67f1f1272d880084d7.1700669207.git.geert+renesas@glider.be